Caleb O. Hale, Sergei T. O'Sullivan, Josey M. Ugrin, McKenna M. Volkman, Emma M. Tracy, John M. Martin, Andrew C. Hogg, Michael J. Giroux
The wheat ( Triticum spp.) Reduced height‐1 ( Rht‐1 ) B1b and D1b semidwarfing alleles have been well studied since their incorporation into modern breeding populations in the 1960s. Useful alternatives to these alleles have been studied in hexaploid wheat ( Triticum aestivum L.), but less so in tetraploid durum wheat ( Triticum turgidum L. subsp. durum ). Most durum varieties are either tall or semidwarf, containing either the Rht‐B1a (tall) or Rht‐B1b (semidwarf) alleles. Because of the dosage‐dependent nature of these alleles, tetraploid semidwarf durum wheat is significantly shorter than hexaploid semidwarf wheat, meaning that in low resource environments, semidwarf durum varieties may yield less and are often too short to be effectively harvested. Thus, the identification of Rht‐1 alleles that confer intermediate height is needed. Near isogenic lines were created to test previously characterized alleles Rht‐B1b ‐E529K, Rht‐A1‐ S50F, and Rht‐A1‐ L358F in field trials to measure grain yield. The Rht‐B1b ‐E529K allele was additionally tested in greenhouse trials to evaluate emergence rates at different planting depths. Rht‐A1‐ S50F and Rht‐A1‐ L358F do slightly affect height but also may reduce yield. Rht‐B1b ‐E529K confers intermediate height, single grain weight, grain protein content, and seedling emergence when compared to lines containing the Rht‐B1a allele or the Rht‐B1b allele. Rht‐B1b ‐E529K also increased grain yield by 8.8% compared to Rht‐B1b in one of the five tested environments. The results show that the Rht‐B1b‐ E529K allele could be useful in regions where drastic decreases in height and reduction in seedling emergence conferred by Rht‐B1b can be detrimental.
{"title":"Durum wheat allele Rht‐B1b‐E529K modifies height and improves emergence","authors":"Caleb O. Hale, Sergei T. O'Sullivan, Josey M. Ugrin, McKenna M. Volkman, Emma M. Tracy, John M. Martin, Andrew C. Hogg, Michael J. Giroux","doi":"10.1002/csc2.70244","DOIUrl":"https://doi.org/10.1002/csc2.70244","url":null,"abstract":"The wheat ( <jats:italic>Triticum</jats:italic> spp.) <jats:italic>Reduced height‐1</jats:italic> ( <jats:italic>Rht‐1</jats:italic> ) <jats:italic>B1b</jats:italic> and <jats:italic>D1b</jats:italic> semidwarfing alleles have been well studied since their incorporation into modern breeding populations in the 1960s. Useful alternatives to these alleles have been studied in hexaploid wheat ( <jats:italic>Triticum aestivum</jats:italic> L.), but less so in tetraploid durum wheat ( <jats:italic>Triticum turgidum</jats:italic> L. subsp. <jats:italic>durum</jats:italic> ). Most durum varieties are either tall or semidwarf, containing either the <jats:italic>Rht‐B1a</jats:italic> (tall) or <jats:italic>Rht‐B1b</jats:italic> (semidwarf) alleles. Because of the dosage‐dependent nature of these alleles, tetraploid semidwarf durum wheat is significantly shorter than hexaploid semidwarf wheat, meaning that in low resource environments, semidwarf durum varieties may yield less and are often too short to be effectively harvested. Thus, the identification of <jats:italic>Rht‐1</jats:italic> alleles that confer intermediate height is needed. Near isogenic lines were created to test previously characterized alleles <jats:italic>Rht‐B1b</jats:italic> ‐E529K, <jats:italic>Rht‐A1‐</jats:italic> S50F, and <jats:italic>Rht‐A1‐</jats:italic> L358F in field trials to measure grain yield. The <jats:italic>Rht‐B1b</jats:italic> ‐E529K allele was additionally tested in greenhouse trials to evaluate emergence rates at different planting depths. <jats:italic>Rht‐A1‐</jats:italic> S50F and <jats:italic>Rht‐A1‐</jats:italic> L358F do slightly affect height but also may reduce yield. <jats:italic>Rht‐B1b</jats:italic> ‐E529K confers intermediate height, single grain weight, grain protein content, and seedling emergence when compared to lines containing the <jats:italic>Rht‐B1a</jats:italic> allele or the <jats:italic>Rht‐B1b</jats:italic> allele. <jats:italic>Rht‐B1b</jats:italic> ‐E529K also increased grain yield by 8.8% compared to <jats:italic>Rht‐B1b</jats:italic> in one of the five tested environments. The results show that the <jats:italic>Rht‐B1b‐</jats:italic> E529K allele could be useful in regions where drastic decreases in height and reduction in seedling emergence conferred by <jats:italic>Rht‐B1b</jats:italic> can be detrimental.","PeriodicalId":10849,"journal":{"name":"Crop Science","volume":"29 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Myriam R. Fernandez, Lobna Abdellatif, Noe Waelchli, Mervin St. Luce, Clemence Muitire, Francis Zvomuya
Intercropping is a sustainable practice becoming increasingly popular in the Canadian Prairies. However, its long‐term impact on diseases in subsequent sole crops is not well understood. We examined root rot and associated fungal communities in durum wheat [ Triticum turgidum L. ssp. durum (Desf.) Husn.], following different ratios of lentil ( Lens culinaris Medik.)–yellow mustard ( Sinapis alba L.), and field pea ( Pisum sativum L.)–oat ( Avena sativa L.) intercrops, and respective monocultures, in a semiarid region of the Canadian Prairies (2018–2019). The previous crop(s) impacted disease severity in durum wheat and had a significant impact on the composition of fungal communities. Durum grown after the mustard monoculture and its high‐ratio intercrop had 15% less severe root rot than after the lentil monoculture and its high‐ratio intercrop, while durum following the oat monoculture and its intercrops had 16% more severe root rot than after mustard and its intercrops. Fusarium species were the most frequent fungal isolates, accounting for 70% of total isolations. The main Fusarium cereal pathogens were >1.7x–25.5x higher following the oat than the mustard monoculture and 2x–3x higher after the pea–oat than the lentil–mustard intercrops. In turn, isolation of the main fungi with biocontrol potential (antagonists) was 4.3x–5x higher after the mustard than oat monoculture, and 2x higher after lentil–mustard than pea–oat. The prevalence of antagonists in mustard‐containing treatments, and their negative correlation with disease levels, suggest a dual mechanism of disease suppression: a direct pathogen inhibition through the mustard's allelopathy and enhanced populations of indigenous microbial antagonists.
间作是一种可持续的做法，在加拿大大草原上越来越流行。然而，其对后续单一作物病害的长期影响尚不清楚。研究了硬粒小麦（Triticum turgidum L. ssp）根系腐病及其相关真菌群落。硬质(Desf)。Husn。]，遵循不同比例的扁豆（Lens culinaris Medik.）-黄芥（Sinapis alba L.）和大田豌豆(Pisum sativum L.) -燕麦（Avena sativa L.）间作，以及各自的单一栽培，在加拿大大草原的半干旱地区（2018-2019）。前茬作物对硬粒小麦病害严重程度有影响，对真菌群落组成有显著影响。芥菜单作及其高比例间作栽培后的硬豆根腐率比小扁豆单作及其高比例间作栽培后的硬豆根腐率低15%，而燕麦单作及其间作栽培后的硬豆根腐率比芥菜及其间作栽培后的硬豆根腐率高16%。镰刀菌是最常见的真菌分离物，占总分离物的70%。主要的谷物镰刀菌致病菌在燕麦后比芥菜单作高1.7 ~ 25.5倍，在豌豆-燕麦间作后比扁豆-芥菜间作高2 ~ 3倍。反过来，具有生物防治潜力的主要真菌（拮抗菌）在芥菜处理后的分离率比单栽培燕麦高4.3 - 5倍，在小扁豆-芥菜处理后的分离率比单栽培豌豆-燕麦高2倍。拮抗剂在含芥菜处理中的普遍存在，以及它们与疾病水平的负相关，表明了疾病抑制的双重机制：通过芥菜的化感作用直接抑制病原体，以及增加本地微生物拮抗剂的种群。
{"title":"Organic intercropping legacy reduces Fusarium pathogens and root rot in subsequent durum wheat","authors":"Myriam R. Fernandez, Lobna Abdellatif, Noe Waelchli, Mervin St. Luce, Clemence Muitire, Francis Zvomuya","doi":"10.1002/csc2.70236","DOIUrl":"https://doi.org/10.1002/csc2.70236","url":null,"abstract":"Intercropping is a sustainable practice becoming increasingly popular in the Canadian Prairies. However, its long‐term impact on diseases in subsequent sole crops is not well understood. We examined root rot and associated fungal communities in durum wheat [ <jats:italic>Triticum turgidum</jats:italic> L. ssp. <jats:italic>durum</jats:italic> (Desf.) Husn.], following different ratios of lentil ( <jats:italic>Lens culinaris</jats:italic> Medik.)–yellow mustard ( <jats:italic>Sinapis alba</jats:italic> L.), and field pea ( <jats:italic>Pisum sativum</jats:italic> L.)–oat ( <jats:italic>Avena sativa</jats:italic> L.) intercrops, and respective monocultures, in a semiarid region of the Canadian Prairies (2018–2019). The previous crop(s) impacted disease severity in durum wheat and had a significant impact on the composition of fungal communities. Durum grown after the mustard monoculture and its high‐ratio intercrop had 15% less severe root rot than after the lentil monoculture and its high‐ratio intercrop, while durum following the oat monoculture and its intercrops had 16% more severe root rot than after mustard and its intercrops. <jats:italic>Fusarium</jats:italic> species were the most frequent fungal isolates, accounting for 70% of total isolations. The main <jats:italic>Fusarium</jats:italic> cereal pathogens were >1.7x–25.5x higher following the oat than the mustard monoculture and 2x–3x higher after the pea–oat than the lentil–mustard intercrops. In turn, isolation of the main fungi with biocontrol potential (antagonists) was 4.3x–5x higher after the mustard than oat monoculture, and 2x higher after lentil–mustard than pea–oat. The prevalence of antagonists in mustard‐containing treatments, and their negative correlation with disease levels, suggest a dual mechanism of disease suppression: a direct pathogen inhibition through the mustard's allelopathy and enhanced populations of indigenous microbial antagonists.","PeriodicalId":10849,"journal":{"name":"Crop Science","volume":"28 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Diógenes Cecchin Silveira, Annamaria Mills, Letícia Winke Dias, Élvio Giasson, Carolina Zambrano Bonotto, Júlia Longhi, Victor Schneider de Ávila, Roberto Luis Weiler, André Pich Brunes, Carine Simioni, Miguel Dall'Agnol
To achieve satisfactory genetic gains, breeding programs must identify and prioritize key traits that affect seed production and quality. This study investigated associations among traits related to seed yield and quality in 84 Paspalum nicorae ecotypes. Path analysis based on multitrait best linear unbiased prediction was applied as a selection tool. Ecotypes were evaluated over 3 years in a randomized block design. Pearson correlations showed that seed yield was strongly associated with pure seed yield (r = 0.90, p < 0.001), number of seeds per inflorescence (r = 0.45, p < 0.01), number of seeds per raceme (r = 0.43, p < 0.01), and thousand seed weight (r = 0.39, p < 0.01). Pure seed yield also correlated with number of seeds per inflorescence (r = 0.54, p < 0.001), number of seeds per raceme (r = 0.50, p < 0.001), and thousand seed weight (r = 0.46, p < 0.01). Claviceps paspali, identified for the first time in P. nicorae in southern Brazil, negatively impacted seed physiological quality, with significant correlations with germination at 7 days (r = −0.34, p < 0.01), 28 days (r = −0.35, p < 0.01), and germination speed index (r = −0.31, p < 0.01). Canonical correlation analysis showed that seed weight increased germination, while physiological quality was negatively affected by pathogen incidence. Path analysis indicated that apparent seed yield and number of seeds per inflorescence were the main determinants of pure seed yield, while number of seeds per raceme and thousand seed weight had secondary effects.
为了获得令人满意的遗传收益，育种计划必须确定并优先考虑影响种子产量和质量的关键性状。研究了84个雀稗生态型种子产量和品质相关性状的相关性。采用基于多性状最优线性无偏预测的通径分析作为选择工具。在随机区组设计中对生态型进行了3年的评估。Pearson相关分析表明，种子产量与纯种子产量（r = 0.90, p < 0.001）、每花序种子数（r = 0.45, p < 0.01）、每总状花序种子数（r = 0.43, p < 0.01）和千粒重（r = 0.39, p < 0.01）密切相关。纯种子产量也与每花序种子数（r = 0.54, p < 0.001）、每总状花序种子数（r = 0.50, p < 0.001）和千粒重（r = 0.46, p < 0.01）相关。在巴西南部nicorae中首次鉴定到的雀稗（Claviceps paspali）对种子生理品质有负向影响，与萌发7 d （r = - 0.34, p < 0.01）、28 d （r = - 0.35, p < 0.01）和萌发速度指数（r = - 0.31, p < 0.01）呈显著相关。典型相关分析表明，种子重对种子萌发有促进作用，而病原菌发病率对种子生理品质有负向影响。通径分析表明，表观种子产量和单花序种子数是纯种子产量的主要决定因素，单总状花序种子数和千粒重是次要影响因素。
{"title":"Correlations based on mixed models as selection criteria for breeding programs targeting seed production and quality in Paspalum nicorae Parodi ecotypes","authors":"Diógenes Cecchin Silveira, Annamaria Mills, Letícia Winke Dias, Élvio Giasson, Carolina Zambrano Bonotto, Júlia Longhi, Victor Schneider de Ávila, Roberto Luis Weiler, André Pich Brunes, Carine Simioni, Miguel Dall'Agnol","doi":"10.1002/csc2.70242","DOIUrl":"https://doi.org/10.1002/csc2.70242","url":null,"abstract":"To achieve satisfactory genetic gains, breeding programs must identify and prioritize key traits that affect seed production and quality. This study investigated associations among traits related to seed yield and quality in 84 <i>Paspalum nicorae</i> ecotypes. Path analysis based on multitrait best linear unbiased prediction was applied as a selection tool. Ecotypes were evaluated over 3 years in a randomized block design. Pearson correlations showed that seed yield was strongly associated with pure seed yield (<i>r</i> = 0.90, <i>p</i> < 0.001), number of seeds per inflorescence (<i>r</i> = 0.45, <i>p</i> < 0.01), number of seeds per raceme (<i>r</i> = 0.43, <i>p</i> < 0.01), and thousand seed weight (<i>r</i> = 0.39, <i>p</i> < 0.01). Pure seed yield also correlated with number of seeds per inflorescence (<i>r</i> = 0.54, <i>p</i> < 0.001), number of seeds per raceme (<i>r</i> = 0.50, <i>p</i> < 0.001), and thousand seed weight (<i>r</i> = 0.46, <i>p</i> < 0.01). <i>Claviceps paspali</i>, identified for the first time in <i>P. nicorae</i> in southern Brazil, negatively impacted seed physiological quality, with significant correlations with germination at 7 days (<i>r</i> = −0.34, <i>p</i> < 0.01), 28 days (<i>r</i> = −0.35, <i>p</i> < 0.01), and germination speed index (<i>r</i> = −0.31, <i>p</i> < 0.01). Canonical correlation analysis showed that seed weight increased germination, while physiological quality was negatively affected by pathogen incidence. Path analysis indicated that apparent seed yield and number of seeds per inflorescence were the main determinants of pure seed yield, while number of seeds per raceme and thousand seed weight had secondary effects.","PeriodicalId":10849,"journal":{"name":"Crop Science","volume":"84 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Myriam R. Fernandez, Lobna Abdellatif, Noe Waelchli, Mervin St. Luce, Clemence Muitire, Francis Zvomuya
Intercropping a grain legume with a grain nonlegume is of increased interest by producers in the Canadian Prairies, especially under organic production where intercropping is an alternative to the lack of economic returns of green manure or summer fallow. Information on the impacts of intercropping on root rot, a significant challenge for legume crops, is needed. The objective of this organic study, conducted over 2 years (2017–2018) in the semiarid Canadian Prairies, was to determine how intercrops of lentil ( Lens culinaris Medik.)–yellow mustard ( Sinapis alba L.) and field pea ( Pisum sativum L.)–oat ( Avena sativa L.), at different seeding ratios, might affect in‐season root rot development and associated fungal communities. This 2‐year study showed that the impacts of intercropping varied between crop combinations and among fungal species. Multiple pathogens, as well as saprophytes, were associated with the intercrops and respective monocultures, with most being Fusarium species. For intercropped lentil, there was a >50% reduction in the mean root rot severity, and an 11% reduction in the isolation of total Fusarium species, compared to its monoculture. These results suggest disease suppression in the intercropped lentil, which might be attributed to allelopathy from mustard leading to an increase in fungi with biocontrol potential (antagonists). These antagonist fungi were 84% higher in lentil intercropped with a full mustard ratio than in its monoculture. In contrast, root rot in pea intercropped with oat was mostly higher than in the pea monoculture, attributed to the prevalence of similar species, including Fusarium pathogens, common to both crop species.
在加拿大大草原上，豆科作物与非豆科作物的间作越来越引起生产者的兴趣，特别是在有机生产中，间作是一种替代缺乏绿肥或夏季休耕经济回报的选择。需要关于间作对根腐病影响的信息，根腐病是豆科作物面临的一个重大挑战。这项有机研究在半干旱的加拿大大草原进行了两年多（2017-2018年），目的是确定小扁豆（Lens culinaris Medik）的间作如何影响植物的生长。-黄芥（Sinapis alba L.）和豌豆(Pisum sativum L.) -燕麦（Avena sativa L.）在不同的播种比例下，可能会影响当季根腐病的发育和相关真菌群落。这项为期2年的研究表明，间作的影响因作物组合和真菌种类而异。间作和各自的单一栽培中存在多种病原菌和腐生菌，其中大部分是镰刀菌。与单作相比，间作扁豆的平均根腐病严重程度降低了50%，总镰刀菌种类的分离率降低了11%。这些结果表明间作扁豆的疾病抑制可能是由于芥菜的化感作用导致具有生物防治潜力的真菌（拮抗剂）增加。这些拮抗真菌在小扁豆间作全芥菜比单作时高出84%。相比之下，豌豆间作燕麦的根腐率大多高于豌豆单作，这是由于两种作物共有的相似物种，包括镰刀菌病原体的流行。
{"title":"Root rot suppression mechanisms in lentil promoted by organic intercropping","authors":"Myriam R. Fernandez, Lobna Abdellatif, Noe Waelchli, Mervin St. Luce, Clemence Muitire, Francis Zvomuya","doi":"10.1002/csc2.70238","DOIUrl":"https://doi.org/10.1002/csc2.70238","url":null,"abstract":"Intercropping a grain legume with a grain nonlegume is of increased interest by producers in the Canadian Prairies, especially under organic production where intercropping is an alternative to the lack of economic returns of green manure or summer fallow. Information on the impacts of intercropping on root rot, a significant challenge for legume crops, is needed. The objective of this organic study, conducted over 2 years (2017–2018) in the semiarid Canadian Prairies, was to determine how intercrops of lentil ( <jats:italic>Lens culinaris</jats:italic> Medik.)–yellow mustard ( <jats:italic>Sinapis alba</jats:italic> L.) and field pea ( <jats:italic>Pisum sativum</jats:italic> L.)–oat ( <jats:italic>Avena sativa</jats:italic> L.), at different seeding ratios, might affect in‐season root rot development and associated fungal communities. This 2‐year study showed that the impacts of intercropping varied between crop combinations and among fungal species. Multiple pathogens, as well as saprophytes, were associated with the intercrops and respective monocultures, with most being <jats:italic>Fusarium</jats:italic> species. For intercropped lentil, there was a >50% reduction in the mean root rot severity, and an 11% reduction in the isolation of total <jats:italic>Fusarium</jats:italic> species, compared to its monoculture. These results suggest disease suppression in the intercropped lentil, which might be attributed to allelopathy from mustard leading to an increase in fungi with biocontrol potential (antagonists). These antagonist fungi were 84% higher in lentil intercropped with a full mustard ratio than in its monoculture. In contrast, root rot in pea intercropped with oat was mostly higher than in the pea monoculture, attributed to the prevalence of similar species, including <jats:italic>Fusarium</jats:italic> pathogens, common to both crop species.","PeriodicalId":10849,"journal":{"name":"Crop Science","volume":"21 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146121998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Renan Uhdre, Edicarlos Peterlini, Rodrigo Ivan Contreras-Soto, Carlos Alberto Scapim, Marilyn L. Warburton
The stay-green trait enables plants to sustain photosynthesis under severe biotic and abiotic stresses and is positively correlated with grain yield in maize (Zea mays L). Despite its importance, information on the inheritance and genetic basis of stay-green in tropical maize remains limited. This study used genome-wide association study (GWAS) to identify chromosomal regions and candidate genes associated with stay-green. Using 350,643 high-quality genome-wide single nucleotide polymorphism (SNP) markers generated through genotyping-by-sequencing of 320 tropical maize inbred lines, we performed GWAS for stay-green using phenotypic data collected in two environments during the 2017/2018 season in Brazil. The experimental design was an α-lattice design with three replicates. GWAS identified 27 significant SNPs (p < 0.05) associated with stay-green, from which 27 candidate genes were inferred based on their proximity (±5 kb) to these SNPs and their functional annotation from the B73 maize reference genome (AGPv4). Pathway analysis revealed 71 unique (although frequently related) biological pathways (p < 0.02), including processes related to sterol, mannitol, UDP-beta-L-arabinose, hydroxycinnamic acid amides, and cuticular wax biosynthesis, spermidine regulation, and jasmonate signaling, all mechanisms known to influence drought stress responses. These results provide valuable genetic resources and candidate markers for breeding for improved stay-green tropical maize, with potential for developing breeder-friendly molecular markers to facilitate selection.
{"title":"Genome-wide association study and pathway analysis to dissect the genetic control of stay-green in a Brazilian panel of tropical maize inbred lines","authors":"Renan Uhdre, Edicarlos Peterlini, Rodrigo Ivan Contreras-Soto, Carlos Alberto Scapim, Marilyn L. Warburton","doi":"10.1002/csc2.70237","DOIUrl":"https://doi.org/10.1002/csc2.70237","url":null,"abstract":"The stay-green trait enables plants to sustain photosynthesis under severe biotic and abiotic stresses and is positively correlated with grain yield in maize (<i>Zea mays</i> L). Despite its importance, information on the inheritance and genetic basis of stay-green in tropical maize remains limited. This study used genome-wide association study (GWAS) to identify chromosomal regions and candidate genes associated with stay-green. Using 350,643 high-quality genome-wide single nucleotide polymorphism (SNP) markers generated through genotyping-by-sequencing of 320 tropical maize inbred lines, we performed GWAS for stay-green using phenotypic data collected in two environments during the 2017/2018 season in Brazil. The experimental design was an α-lattice design with three replicates. GWAS identified 27 significant SNPs (<i>p</i> < 0.05) associated with stay-green, from which 27 candidate genes were inferred based on their proximity (±5 kb) to these SNPs and their functional annotation from the B73 maize reference genome (AGPv4). Pathway analysis revealed 71 unique (although frequently related) biological pathways (<i>p</i> < 0.02), including processes related to sterol, mannitol, UDP-beta-L-arabinose, hydroxycinnamic acid amides, and cuticular wax biosynthesis, spermidine regulation, and jasmonate signaling, all mechanisms known to influence drought stress responses. These results provide valuable genetic resources and candidate markers for breeding for improved stay-green tropical maize, with potential for developing breeder-friendly molecular markers to facilitate selection.","PeriodicalId":10849,"journal":{"name":"Crop Science","volume":"78 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Simon Fraher, Jonathan Kinczyk, Gabriel de Siqueira Gesteira, Chris Heim, Sharon Williamson, Bode A. Olukolu, Guilherme da Silva Pereira, Marcelo Mollinari, John P. Hamilton, C. Robin Buell, Zhao‐Bang Zeng, Lina Quesada‐Ocampo, G. Craig Yencho
Fusarium oxysporum f. sp. batatas , the causal agent of Fusarium wilt disease, was once the most damaging pathogen of sweetpotato in the United States. Breeding for cultivar resistance has largely addressed this issue, however, little is known about the genetic basis for resistance. Historically, sweetpotato breeders have relied on the high heritability of Fusarium wilt resistance, so identification of a region controlling resistance would be a major first step in implementing marker‐assisted selection for this trait. We assayed a biparental mapping population, NCDM04‐0001 × ‘Covington’ (DC), consisting of a susceptible by resistant cross composed of 454 progenies, for resistance to Fusarium wilt disease using visual assessments and an ordinal disease severity rating scale. Parental and check lines performed as expected, and the DC population exhibited segregation for resistance across trials over 3 years and in a joint analysis. We next performed quantitative trait locus (QTL) analyses using a linkage map based on the Ipomoea trifida diploid reference genome. Across multiple trials, we repeatedly detected a major QTL on chromosome 10, herein named qIbFo‐10.1. This QTL had a heritability of 33.8%, suggesting that a single locus explains a large amount of variation for resistance to this critically important trait. A basic local alignment search tool revealed several candidate genes: itf10g19820 (transcriptional factor B3 family protein/auxin‐responsive factor AUX/IAA‐related), four LRR‐kinases (leucine‐rich repeat receptor kinase) (itf10g21910, itf10g19200, itf10g19260, and itf10g20000), and two toll‐interleukin‐resistance genes (itf10g20200 and itf10g20220). Future efforts should develop molecular tools for Fusarium wilt resistance breeding, resulting in shorter breeding cycles and faster variety releases.
{"title":"Discovery of a major QTL for resistance to Fusarium wilt ( Fusarium oxysporum f. sp. batatas ) in the hexaploid Covington sweetpotato","authors":"Simon Fraher, Jonathan Kinczyk, Gabriel de Siqueira Gesteira, Chris Heim, Sharon Williamson, Bode A. Olukolu, Guilherme da Silva Pereira, Marcelo Mollinari, John P. Hamilton, C. Robin Buell, Zhao‐Bang Zeng, Lina Quesada‐Ocampo, G. Craig Yencho","doi":"10.1002/csc2.70239","DOIUrl":"https://doi.org/10.1002/csc2.70239","url":null,"abstract":"<jats:italic>Fusarium oxysporum</jats:italic> f. sp. <jats:italic>batatas</jats:italic> , the causal agent of <jats:italic>Fusarium</jats:italic> wilt disease, was once the most damaging pathogen of sweetpotato in the United States. Breeding for cultivar resistance has largely addressed this issue, however, little is known about the genetic basis for resistance. Historically, sweetpotato breeders have relied on the high heritability of <jats:italic>Fusarium</jats:italic> wilt resistance, so identification of a region controlling resistance would be a major first step in implementing marker‐assisted selection for this trait. We assayed a biparental mapping population, NCDM04‐0001 × ‘Covington’ (DC), consisting of a susceptible by resistant cross composed of 454 progenies, for resistance to <jats:italic>Fusarium</jats:italic> wilt disease using visual assessments and an ordinal disease severity rating scale. Parental and check lines performed as expected, and the DC population exhibited segregation for resistance across trials over 3 years and in a joint analysis. We next performed quantitative trait locus (QTL) analyses using a linkage map based on the <jats:italic>Ipomoea trifida</jats:italic> diploid reference genome. Across multiple trials, we repeatedly detected a major QTL on chromosome 10, herein named qIbFo‐10.1. This QTL had a heritability of 33.8%, suggesting that a single locus explains a large amount of variation for resistance to this critically important trait. A basic local alignment search tool revealed several candidate genes: itf10g19820 (transcriptional factor B3 family protein/auxin‐responsive factor AUX/IAA‐related), four LRR‐kinases (leucine‐rich repeat receptor kinase) (itf10g21910, itf10g19200, itf10g19260, and itf10g20000), and two toll‐interleukin‐resistance genes (itf10g20200 and itf10g20220). Future efforts should develop molecular tools for <jats:italic>Fusarium</jats:italic> wilt resistance breeding, resulting in shorter breeding cycles and faster variety releases.","PeriodicalId":10849,"journal":{"name":"Crop Science","volume":"381 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146095785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Casey D. Kennedy, Juan Zalapa, Peter Jeranyama, Giverson Mupambi, David Millar, Adrian Wiegman, Molly Welsh, Anthony Buda
For decades, the top producer of cranberries (Vaccinium macrocarpon Ait.) worldwide was Massachusetts. Today, among the states that grow cranberries commercially, Massachusetts ranks second nationally in overall cranberry production, but last in crop yield. In this study, we explore the causes of low crop yields by analyzing multiple datasets, including 4-year grower records for 213 beds (513 ha, or 11% of the state's cranberry acreage), to quantify the effects of cultivar, fertilizer use, pesticide applications, and irrigation management on crop yields. We find that low crop yields in Massachusetts are primarily due to the prevalence of native varieties, such as Early Black (YEB = 14.6 Mg ha−1). By comparison, Mullica Queen, a popular second-generation hybrid cultivar, produces 229% more fruit (YMQ= 47.9 Mg ha−1) and receives 146% more nitrogen (N) fertilizer, but is managed similarly for phosphorus, pests, and irrigation. Collectively, these results point to better utilization and allocation of N fertilizer for reproductive growth in hybrid cultivars, such as Mullica Queen. An economic analysis of return on investment for renovating and replanting Early Black beds with Mullica Queen resulted in an 11-year payback time, which was most sensitive to the price of cranberries, cost of replanting with Mullica Queen, and state-funded renovation grants. Given the current economics of the cranberry industry, we question the long-term viability of farms planted with Early Black and even Howes cranberries. With increased investments to support replanting of 20% of Early Black acreage with Mullica Queen, Massachusetts crop yields would increase by 25%.
{"title":"Genetics as the limiting factor in cranberry production: Field data to support replanting with next-generation cranberry hybrids","authors":"Casey D. Kennedy, Juan Zalapa, Peter Jeranyama, Giverson Mupambi, David Millar, Adrian Wiegman, Molly Welsh, Anthony Buda","doi":"10.1002/csc2.70208","DOIUrl":"https://doi.org/10.1002/csc2.70208","url":null,"abstract":"For decades, the top producer of cranberries (<i>Vaccinium macrocarpon</i> Ait.) worldwide was Massachusetts. Today, among the states that grow cranberries commercially, Massachusetts ranks second nationally in overall cranberry production, but last in crop yield. In this study, we explore the causes of low crop yields by analyzing multiple datasets, including 4-year grower records for 213 beds (513 ha, or 11% of the state's cranberry acreage), to quantify the effects of cultivar, fertilizer use, pesticide applications, and irrigation management on crop yields. We find that low crop yields in Massachusetts are primarily due to the prevalence of native varieties, such as Early Black (<i>Y</i><sub>EB</sub> = 14.6 Mg ha<sup>−1</sup>). By comparison, Mullica Queen, a popular second-generation hybrid cultivar, produces 229% more fruit (<i>Y</i><sub>MQ</sub><i><sub> </sub></i>= 47.9 Mg ha<sup>−1</sup>) and receives 146% more nitrogen (N) fertilizer, but is managed similarly for phosphorus, pests, and irrigation. Collectively, these results point to better utilization and allocation of N fertilizer for reproductive growth in hybrid cultivars, such as Mullica Queen. An economic analysis of return on investment for renovating and replanting Early Black beds with Mullica Queen resulted in an 11-year payback time, which was most sensitive to the price of cranberries, cost of replanting with Mullica Queen, and state-funded renovation grants. Given the current economics of the cranberry industry, we question the long-term viability of farms planted with Early Black and even Howes cranberries. With increased investments to support replanting of 20% of Early Black acreage with Mullica Queen, Massachusetts crop yields would increase by 25%.","PeriodicalId":10849,"journal":{"name":"Crop Science","volume":"42 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146095784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Grant T. Billings, Daniel Restrepo-Montoya, Laine A. Dentinger, Jonathan W. Zirkel, B. Todd Campbell, Don C. Jones, Quentin D. Read, Peng W. Chee, Brian E. Scheffler, Candace H. Haigler, Amanda M. Hulse-Kemp, Jodi A. Scheffler
Common garden experiments have provided great insights into crop adaptation across many systems. Cotton (Gossypium spp.) cultivars have changed in the 20th and 21st centuries, but breeders have not quantified the degree of these changes. We synthesized a panel of 164 non-genetically modified genotypes, from the private and public sectors, which we refer to as the “US Historical Lines Panel.” We collected historical documentation, including parentage and time of release, to group each genotype into one of four eras. We grew all genotypes in a common garden experiment, collected data, and then used univariate and bivariate statistical methods to analyze the changes in cotton trait genetic architecture over time. Through this comprehensive analysis we found that cotton breeders have improved average cotton fiber quality and yield. The variance for traits and their pairwise correlations have also undergone significant changes. We estimated that the net genetic gain accounts for 46% of the increase in historical fiber yield increase. Our results lay the groundwork for future analysis on the cotton historical lines, providing a long-term historical and phenotypic resource for follow-up experiments.
{"title":"The cotton historical lines project—Part I: History and field evaluation","authors":"Grant T. Billings, Daniel Restrepo-Montoya, Laine A. Dentinger, Jonathan W. Zirkel, B. Todd Campbell, Don C. Jones, Quentin D. Read, Peng W. Chee, Brian E. Scheffler, Candace H. Haigler, Amanda M. Hulse-Kemp, Jodi A. Scheffler","doi":"10.1002/csc2.70173","DOIUrl":"https://doi.org/10.1002/csc2.70173","url":null,"abstract":"Common garden experiments have provided great insights into crop adaptation across many systems. Cotton (<i>Gossypium</i> spp.) cultivars have changed in the 20th and 21st centuries, but breeders have not quantified the degree of these changes. We synthesized a panel of 164 non-genetically modified genotypes, from the private and public sectors, which we refer to as the “US Historical Lines Panel.” We collected historical documentation, including parentage and time of release, to group each genotype into one of four eras. We grew all genotypes in a common garden experiment, collected data, and then used univariate and bivariate statistical methods to analyze the changes in cotton trait genetic architecture over time. Through this comprehensive analysis we found that cotton breeders have improved average cotton fiber quality and yield. The variance for traits and their pairwise correlations have also undergone significant changes. We estimated that the net genetic gain accounts for 46% of the increase in historical fiber yield increase. Our results lay the groundwork for future analysis on the cotton historical lines, providing a long-term historical and phenotypic resource for follow-up experiments.","PeriodicalId":10849,"journal":{"name":"Crop Science","volume":"58 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146095782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
James O. Nyanapah, Patrick. O. Ayiecho, Julius O. Nyabundi, Washington Otieno, Peter S. Ojiambo
Six sets of 48 maize ( Zea mays L.) inbred lines, and their 96 single crosses generated using the North Carolina Mating Design II system, were evaluated for resistance to gray leaf spot (GLS). The aim of the study was to assess the implications of combining ability, heterotic effects, and potence ratio in breeding for GLS resistance in maize. Inbred lines, crosses, and two local commercial checks were artificially inoculated with Cercospora zeina and evaluated across nine field environments in Western Kenya from 2012 to 2014. Analysis of variance revealed significant ( p ≤ 0.05) differences in disease resistance among inbred lines and their single crosses. Both general combining ability (GCA) and specific combining ability (SCA) effects were significant ( p ≤ 0.05), suggesting that resistance was influenced by both additive and non‐additive genetic factors. However, the sums of squares of GCA were two to four times larger than those of SCA, indicating a greater role of additive genetic effects, although the magnitude varied depending on the genetic set under investigation. Further, there was a strong and significant correlation ( p ≤ 0.05) between the GCA effects of the parental lines and the resistance levels of their hybrid crosses, indicating GCA effects were predictive of hybrid resistance and that reciprocal recurrent selection may be a potential strategy of breeding for GLS resistance. Inbred lines CML202, CML210, and CML373 were the strongest general combiners. The highest SCA effects were observed in crosses such as CML373 × CML168, CML371 × CML168, and CML219 × CML205. Crosses derived from parents within compatible heterotic patterns exhibited significant ( p ≤ 0.05) mid‐parent heterosis, with the cross CML219 × CML123 showing the most pronounced heterotic effect. Other crosses with notable mid‐parent heterosis included CML371 × CML390, CML204 × CML160, and CML394 × CML168. Although the variation in potence ratio estimates indicated that the interactions between loci ranged from complementary to inhibitory epistasis, the most prevalent genetic interaction was overdominance. These findings suggest that breeding strategies to improve GLS resistance in maize should be adapted to the specific genetic backgrounds of parental material. While reciprocal recurrent selection would suit most of the evaluated genotypes, half‐sib and genomic selection could be the most effective in different contexts.
{"title":"Combining ability and heterosis in partial resistance to gray leaf spot in elite maize ( Zea mays L.) genotypes","authors":"James O. Nyanapah, Patrick. O. Ayiecho, Julius O. Nyabundi, Washington Otieno, Peter S. Ojiambo","doi":"10.1002/csc2.70235","DOIUrl":"https://doi.org/10.1002/csc2.70235","url":null,"abstract":"Six sets of 48 maize ( <jats:italic>Zea mays</jats:italic> L.) inbred lines, and their 96 single crosses generated using the North Carolina Mating Design II system, were evaluated for resistance to gray leaf spot (GLS). The aim of the study was to assess the implications of combining ability, heterotic effects, and potence ratio in breeding for GLS resistance in maize. Inbred lines, crosses, and two local commercial checks were artificially inoculated with <jats:italic>Cercospora zeina</jats:italic> and evaluated across nine field environments in Western Kenya from 2012 to 2014. Analysis of variance revealed significant ( <jats:italic>p</jats:italic> ≤ 0.05) differences in disease resistance among inbred lines and their single crosses. Both general combining ability (GCA) and specific combining ability (SCA) effects were significant ( <jats:italic>p</jats:italic> ≤ 0.05), suggesting that resistance was influenced by both additive and non‐additive genetic factors. However, the sums of squares of GCA were two to four times larger than those of SCA, indicating a greater role of additive genetic effects, although the magnitude varied depending on the genetic set under investigation. Further, there was a strong and significant correlation ( <jats:italic>p</jats:italic> ≤ 0.05) between the GCA effects of the parental lines and the resistance levels of their hybrid crosses, indicating GCA effects were predictive of hybrid resistance and that reciprocal recurrent selection may be a potential strategy of breeding for GLS resistance. Inbred lines CML202, CML210, and CML373 were the strongest general combiners. The highest SCA effects were observed in crosses such as CML373 × CML168, CML371 × CML168, and CML219 × CML205. Crosses derived from parents within compatible heterotic patterns exhibited significant ( <jats:italic>p</jats:italic> ≤ 0.05) mid‐parent heterosis, with the cross CML219 × CML123 showing the most pronounced heterotic effect. Other crosses with notable mid‐parent heterosis included CML371 × CML390, CML204 × CML160, and CML394 × CML168. Although the variation in potence ratio estimates indicated that the interactions between loci ranged from complementary to inhibitory epistasis, the most prevalent genetic interaction was overdominance. These findings suggest that breeding strategies to improve GLS resistance in maize should be adapted to the specific genetic backgrounds of parental material. While reciprocal recurrent selection would suit most of the evaluated genotypes, half‐sib and genomic selection could be the most effective in different contexts.","PeriodicalId":10849,"journal":{"name":"Crop Science","volume":"58 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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