Kevin Z. Mganga, Jana Kuhla, Andrea Carminati, Johanna Pausch, Mutez A. Ahmed
Background
Few studies have evaluated the effect of drought on the morpho-physiological characteristics of African C4 grasses. We investigated how drought affects leaf gas exchange characteristics, biomass partitioning, and water use efficiencies of Enteropogon macrostachyus and Cenchrus ciliaris.
Methods
The grasses were grown in a controlled environment under optimum conditions, that is, 70% of the maximum water-holding capacity (WHC) for the first 40 days. Thereafter, half of the columns were maintained under optimum or drought conditions (30% of maximum WHC) for another 20 days.
Results
Under optimum conditions, C. ciliaris showed a significantly higher photosynthetic rate, stomatal conductance, and transpiration rate than E. macrostachyus. Drought decreased the photosynthetic rate, stomatal conductance and transpiration rate only in C. ciliaris. The net photosynthetic rate, stomatal conductance, and leaf transpiration of E. macrostachyus did not differ significantly under optimum and drought conditions. E. macrostachyus showed an increase in its water use efficiencies under drought to a greater extent than C. ciliaris.
Conclusions
Our results demonstrate that C. ciliaris is more sensitive to drought than E. macrostachyus. The decrease in the intercellular CO2 concentration and the increase in stomatal limitation with drought in C. ciliaris and E. macrostachyus suggest that stomatal limitation plays the dominant role in photosynthesis of the studied African C4 grasses.
{"title":"Leaf gas exchange characteristics, biomass partitioning, and water use efficiencies of two C4 African grasses under simulated drought","authors":"Kevin Z. Mganga, Jana Kuhla, Andrea Carminati, Johanna Pausch, Mutez A. Ahmed","doi":"10.1002/glr2.12040","DOIUrl":"https://doi.org/10.1002/glr2.12040","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Few studies have evaluated the effect of drought on the morpho-physiological characteristics of African C<sub>4</sub> grasses. We investigated how drought affects leaf gas exchange characteristics, biomass partitioning, and water use efficiencies of <i>Enteropogon macrostachyus</i> and <i>Cenchrus ciliaris</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The grasses were grown in a controlled environment under optimum conditions, that is, 70% of the maximum water-holding capacity (WHC) for the first 40 days. Thereafter, half of the columns were maintained under optimum or drought conditions (30% of maximum WHC) for another 20 days.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Under optimum conditions, <i>C. ciliaris</i> showed a significantly higher photosynthetic rate, stomatal conductance, and transpiration rate than <i>E. macrostachyus</i>. Drought decreased the photosynthetic rate, stomatal conductance and transpiration rate only in <i>C. ciliaris</i>. The net photosynthetic rate, stomatal conductance, and leaf transpiration of <i>E. macrostachyus</i> did not differ significantly under optimum and drought conditions. <i>E. macrostachyus</i> showed an increase in its water use efficiencies under drought to a greater extent than <i>C. ciliaris</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results demonstrate that <i>C. ciliaris</i> is more sensitive to drought than <i>E. macrostachyus</i>. The decrease in the intercellular CO<sub>2</sub> concentration and the increase in stomatal limitation with drought in <i>C. ciliaris</i> and <i>E. macrostachyus</i> suggest that stomatal limitation plays the dominant role in photosynthesis of the studied African C<sub>4</sub> grasses.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"2 1","pages":"37-45"},"PeriodicalIF":0.0,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12040","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50118173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ciarán Hearn, Michael Egan, Mary Bridget Lynch, Christina Fleming, Michael O'Donovan
Background
Recently, there has been increasing interest in the use of multispecies (MS) swards in dairy grazing systems.
Methods
A plot grazing study was established to investigate the potential contribution of different sward species (perennial ryegrass, legumes and herbs) sown in grazing pastures. Ten sward mixtures were sown, ranging in complexity from a perennial ryegrass (PRG) monoculture to binary mixtures including either forage legumes or herbs to a five-species mixture; four different nitrogen (N) application rates of 0, 100, 150 and 200 kg N ha−1 were applied to each sward.
Results
Species abundance for all sward species components was associated with the interaction of time point and sward mixture; species abundance for all sward components, except PRG, was associated with the interaction of N application and sward mixture. The interactions of time point and sward mixture, and time point and N application rate, were associated with all analysed sward chemical components, except for sward digestibility.
Conclusions
Increased N application rates reduced the level of clover in all sward mixtures. Increased levels of white clover led to increased sward crude protein levels; the inclusion of ribwort plantain led to some seasonal variation in the nutritive value of swards.
近年来，人们对多物种草地在奶牛放牧系统中的应用越来越感兴趣。方法采用样地放牧研究方法，探讨不同禾本科牧草(多年生黑麦草、豆科植物和草本植物)在放牧草地上的潜在贡献。播种了10种禾草混合物，其复杂性从多年生黑麦草(PRG)单一栽培到二元混合物，包括饲料豆类或草本植物，再到五种混合物;每个草地分别施氮量为0、100、150和200 kg N ha−1。结果禾本科各物种组分的物种丰度与时间点和禾本科混交种的相互作用有关;除PRG外，所有禾草成分的物种丰度与施氮和禾草混合的交互作用有关。除草的消化率外，时间点与草混合物的交互作用、时间点与施氮量对草的化学成分均有显著影响。结论施氮量的增加降低了三叶草的含量。白三叶草添加量的增加导致叶片粗蛋白质水平的增加;车前草的加入导致了草的营养价值有一定的季节变化。
{"title":"Seasonal variations in nutritive and botanical composition properties of multispecies grazing swards over an entire dairy grazing season","authors":"Ciarán Hearn, Michael Egan, Mary Bridget Lynch, Christina Fleming, Michael O'Donovan","doi":"10.1002/glr2.12037","DOIUrl":"10.1002/glr2.12037","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Recently, there has been increasing interest in the use of multispecies (MS) swards in dairy grazing systems.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A plot grazing study was established to investigate the potential contribution of different sward species (perennial ryegrass, legumes and herbs) sown in grazing pastures. Ten sward mixtures were sown, ranging in complexity from a perennial ryegrass (PRG) monoculture to binary mixtures including either forage legumes or herbs to a five-species mixture; four different nitrogen (N) application rates of 0, 100, 150 and 200 kg N ha<sup>−1</sup> were applied to each sward.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Species abundance for all sward species components was associated with the interaction of time point and sward mixture; species abundance for all sward components, except PRG, was associated with the interaction of N application and sward mixture. The interactions of time point and sward mixture, and time point and N application rate, were associated with all analysed sward chemical components, except for sward digestibility.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Increased N application rates reduced the level of clover in all sward mixtures. Increased levels of white clover led to increased sward crude protein levels; the inclusion of ribwort plantain led to some seasonal variation in the nutritive value of swards.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 4","pages":"221-233"},"PeriodicalIF":0.0,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85241224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Justin C. Burt, Lisa L. Baxter, Christopher G. Prevatt, Mary Kimberly Mullenix, R. Lawton Stewart Jr., Jennifer J. Tucker
Background
Bermudagrass (Cynodon spp.) is one of the most common perennial warm-season forages grown in the Southeastern United States. The incorporation of alfalfa (Medicago sativa) into bermudagrass pastures could serve as an alternative source of nitrogen (N) while also improving the nutritive value of the forage base.
Methods
A 2-year grazing evaluation arranged in a randomized complete block design was conducted from May to September 2018 (Year 1) and May–August 2019 (Year 2) in Tifton, GA, USA. The objective was to compare the production of alfalfa–bermudagrass mixed pastures (BGA) with bermudagrass monoculture pastures with (BGN) or without (BG) the application of synthetic nitrogen on forage production and stocker cattle performance.
Results
Differences were observed for average daily gain (p = 0.10), gain per hectare (p = 0.02) and stocking rate (p = 0.01), in that BGA was greatest compared to BGN and BG, which did not differ from each other. Furthermore, BGA had increased forage crude protein (p = 0.01) and total digestible nutrients (p = 0.01) compared to BGN and BG. Finally, BGA provided the greatest economic return per hectare compared to BG or BGN.
Conclusions
These data illustrate improved animal performance and forage nutritive value using alfalfa–bermudagrass systems and offer a viable option for producers seeking alternatives to synthetic N sources for bermudagrass pastures in the Southeastern United States.
{"title":"Improving bermudagrass in the Southeastern United States with alfalfa as an alternative nitrogen source in grazing systems","authors":"Justin C. Burt, Lisa L. Baxter, Christopher G. Prevatt, Mary Kimberly Mullenix, R. Lawton Stewart Jr., Jennifer J. Tucker","doi":"10.1002/glr2.12038","DOIUrl":"https://doi.org/10.1002/glr2.12038","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Bermudagrass (<i>Cynodon</i> spp.) is one of the most common perennial warm-season forages grown in the Southeastern United States. The incorporation of alfalfa (<i>Medicago sativa</i>) into bermudagrass pastures could serve as an alternative source of nitrogen (N) while also improving the nutritive value of the forage base.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A 2-year grazing evaluation arranged in a randomized complete block design was conducted from May to September 2018 (Year 1) and May–August 2019 (Year 2) in Tifton, GA, USA. The objective was to compare the production of alfalfa–bermudagrass mixed pastures (BGA) with bermudagrass monoculture pastures with (BGN) or without (BG) the application of synthetic nitrogen on forage production and stocker cattle performance.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Differences were observed for average daily gain (<i>p</i> = 0.10), gain per hectare (<i>p</i> = 0.02) and stocking rate (<i>p</i> = 0.01), in that BGA was greatest compared to BGN and BG, which did not differ from each other. Furthermore, BGA had increased forage crude protein (<i>p</i> = 0.01) and total digestible nutrients (<i>p</i> = 0.01) compared to BGN and BG. Finally, BGA provided the greatest economic return per hectare compared to BG or BGN.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These data illustrate improved animal performance and forage nutritive value using alfalfa–bermudagrass systems and offer a viable option for producers seeking alternatives to synthetic N sources for bermudagrass pastures in the Southeastern United States.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 4","pages":"280-289"},"PeriodicalIF":0.0,"publicationDate":"2023-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12038","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137698805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Strong selection can occur during switchgrass sward establishment. Differences in establishment selection due to environment or management could provide information on genotype-by-environment variation and could influence strategies for breeding perennial grasses.
Methods
Leaf samples were collected before sward establishment and from 3-year-old swards for two breeding groups (lowland and hybrid) at three locations. Within two locations, samples were collected from paired fertilized (112 kg N ha−1) and unfertilized plots. Allele frequencies from pooled DNA samples were studied through multivariate analysis of variance, genomewide trait predictions (heading date and winter survivorship), and genomically estimated breeding values (GEBVs) for individual sward survival within an independent data set.
Results
This study found only minor variations in selection due to location or management. Predicted heading dates of the hybrid population had significant changes due to fertilization and location. There were strong correlations among sward establishment survival GEBVs between growing environments (hybrid r = 0.77; gulf r = 0.97). Interestingly, this study found a small number of genotypes that were over-represented in established swards across all growing environments.
Conclusions
This study reinforces a prior report of selection during sward establishment and indicates that only a small degree of establishment selection is location-specific within these diverse growing conditions.
在柳枝稷生长过程中会发生强选择。由于环境或管理导致的生境选择差异可以提供基因型随环境变化的信息，并可能影响多年生草的育种策略。方法在3个地点采集草地建立前和3年生禾草的叶片样本，分为低地和杂交两个育种组。在两个地点，从成对施肥(112 kg N ha - 1)和未施肥地块采集样本。通过多变量方差分析、全基因组性状预测(抽穗日期和冬季存活率)以及独立数据集中个体swward存活率的基因组估计育种值(GEBVs)，研究了混合DNA样本的等位基因频率。结果本研究发现，由于地点或管理，在选择上只有很小的差异。杂交群体的抽穗期预测受施肥和位置的影响有显著的变化。不同生长环境间草种成活gebv有很强的相关性(杂交r = 0.77;海湾r = 0.97)。有趣的是，这项研究发现，在所有生长环境中，少数基因型在已建立的植物中都有过度的代表。本研究强化了先前关于草木生长过程中选择的报道，表明在这些不同的生长条件下，只有一小部分草木生长选择是特定于地点的。
{"title":"Switchgrass sward establishment selection is consistent across multiple environments and fertilization levels","authors":"Neal W. Tilhou, Michael D. Casler","doi":"10.1002/glr2.12035","DOIUrl":"10.1002/glr2.12035","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Strong selection can occur during switchgrass sward establishment. Differences in establishment selection due to environment or management could provide information on genotype-by-environment variation and could influence strategies for breeding perennial grasses.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Leaf samples were collected before sward establishment and from 3-year-old swards for two breeding groups (lowland and hybrid) at three locations. Within two locations, samples were collected from paired fertilized (112 kg N ha<sup>−1</sup>) and unfertilized plots. Allele frequencies from pooled DNA samples were studied through multivariate analysis of variance, genomewide trait predictions (heading date and winter survivorship), and genomically estimated breeding values (GEBVs) for individual sward survival within an independent data set.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>This study found only minor variations in selection due to location or management. Predicted heading dates of the hybrid population had significant changes due to fertilization and location. There were strong correlations among sward establishment survival GEBVs between growing environments (hybrid <i>r</i> = 0.77; gulf <i>r</i> = 0.97). Interestingly, this study found a small number of genotypes that were over-represented in established swards across all growing environments.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study reinforces a prior report of selection during sward establishment and indicates that only a small degree of establishment selection is location-specific within these diverse growing conditions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 4","pages":"252-261"},"PeriodicalIF":0.0,"publicationDate":"2023-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12035","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76613841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andres Locatelli, Lucia Gutierrez, Olivier Duchene, Pablo R. Speranza, Valentin D. Picasso Risso
Background
Kernza® intermediate wheatgrass is a perennial grain and forage crop that can provide several ecosystem services. Major research efforts focused on Kernza have taken place in high latitudes. The goal of this study was to evaluate, for the first time, the agronomic performance of Kernza in a low-latitude region with mild winters.
Methods
A KS-cycle 4 Kernza population (A) was planted in spring in Wisconsin, USA, and selected in one cycle for lower vernalization requirements, obtaining a new population (B). These two populations, at three nitrogen (N) fertilization rates, were evaluated in a full factorial, completely randomized field experiment in Uruguay over 2 years.
Results
The populations were similar in grain yields and flowering time in the 1st year, but population B had 63% lower grain yield in the 2nd year and 20% lower forage yield throughout the experiment. Increasing the N rate to 160 kg ha−1 led to a 63% increase in grain yield and 28% increase in forage yield across populations. Forage yields and nutritive values were similar to those reported in the northern hemisphere. However, grain yields for both the 1st (316 kg ha−1) and 2nd year (41 kg ha−1) were lower due to reduced flowering and weed competition.
Conclusions
Expansion of Kernza to lower-latitude regions will require further breeding to improve reproductive performance.
Kernza®中间小麦草是一种多年生粮食和饲料作物，可以提供多种生态系统服务。主要的研究工作集中在高纬度地区。本研究的目的是首次评价克恩扎在暖冬低纬度地区的农艺表现。方法在美国威斯康辛州春季种植一个KS-cycle 4 Kernza群体(A)，在一个周期内选择较低的春化需求，获得一个新群体(B)。在乌拉圭进行为期2年的全因子、完全随机田间试验，对这两个群体在3种氮肥施用量下进行评价。结果2个群体在第1年的粮食产量和开花时间上基本一致，但种群B在第2年的粮食产量比第2年低63%，整个试验期间的牧草产量比第2年低20%。将施氮量提高到160 kg ha - 1，籽粒产量提高63%，牧草产量提高28%。草料产量和营养价值与北半球的报道相似。然而，由于开花和杂草竞争减少，第一年(316 kg ha - 1)和第二年(41 kg ha - 1)的粮食产量都有所下降。结论在低纬度地区扩展Kernza需要进一步的育种来提高繁殖性能。
{"title":"Agronomic assessment of two populations of intermediate wheatgrass—Kernza® (Thinopyrum intermedium) in temperate South America","authors":"Andres Locatelli, Lucia Gutierrez, Olivier Duchene, Pablo R. Speranza, Valentin D. Picasso Risso","doi":"10.1002/glr2.12032","DOIUrl":"10.1002/glr2.12032","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Kernza® intermediate wheatgrass is a perennial grain and forage crop that can provide several ecosystem services. Major research efforts focused on Kernza have taken place in high latitudes. The goal of this study was to evaluate, for the first time, the agronomic performance of Kernza in a low-latitude region with mild winters.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A KS-cycle 4 Kernza population (A) was planted in spring in Wisconsin, USA, and selected in one cycle for lower vernalization requirements, obtaining a new population (B). These two populations, at three nitrogen (N) fertilization rates, were evaluated in a full factorial, completely randomized field experiment in Uruguay over 2 years.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The populations were similar in grain yields and flowering time in the 1st year, but population B had 63% lower grain yield in the 2nd year and 20% lower forage yield throughout the experiment. Increasing the N rate to 160 kg ha<sup>−1</sup> led to a 63% increase in grain yield and 28% increase in forage yield across populations. Forage yields and nutritive values were similar to those reported in the northern hemisphere. However, grain yields for both the 1st (316 kg ha<sup>−1</sup>) and 2nd year (41 kg ha<sup>−1</sup>) were lower due to reduced flowering and weed competition.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Expansion of Kernza to lower-latitude regions will require further breeding to improve reproductive performance.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 4","pages":"262-278"},"PeriodicalIF":0.0,"publicationDate":"2023-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12032","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86549634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bosco Kidake Kisambo, Oliver V. Wasonga, Oscar K. Koech, George N. Karuku
Background
Livestock production is an economically significant activity in grassland-based production systems with herbivory, a critical process in modifying plant structure and regulating biomass dynamics in these areas.
Methods
A grazing simulation experiment was undertaken in a semi-arid environment in Kenya to determine the effects of clipping frequency and intensity on the morphology and productivity of Cenchrus ciliaris and Panicum maximum grass ecotypes. The ecotypes were clipped at different frequencies (every 2, 4, and 12 weeks) and different intensities (5, 10, and 15 cm clipping heights). The morphological responses of the grass ecotypes and biomass yields were determined.
Results
The grass ecotypes showed significantly (p < 0.05) varied responses to cutting frequency and intensity. Morphological parameters, tillering, and biomass production were all affected by clipping frequency and intensity. The highest dry matter (DM) yields were recorded under low frequency (LF) clipping, followed by moderate frequency (MF) clipping and high frequency (HF) clipping. LF clipping in C. ciliaris ecotype Kilifi was 20% and 31% more compared to MF and HF clipping. No significant difference in yields was found by cutting the C. ciliaris ecotype Magadi at 4- and 12-week intervals, even though clipping at 2-week intervals cumulatively yielded less biomass. There was a biomass yield reduction in P. maximum ecotype Taveta of 23% and 25% for MF and HF clipping, respectively, while for ecotype Isinya, the reduction was 13% and 15% for MF and HF, respectively. Clipping intensity had a significant (p < 0.05) effect on cumulative yields in C. ciliaris ecotypes, but not P. maximum. Ecotypic differences were apparent in both C. ciliaris and P. maximum ecotype DM yields.
Conclusions
The results in this study suggest that clipping range grass ecotypes less frequently (4- and 12-week intervals) and at 10 and 15 cm stubble heights results in higher biomass yields. Generally, LF and MF grazing and cutting strategies are advantageous for semi-arid lands. Combinations of frequent and high-intensity utilization grazing strategies should be discouraged as they are likely to lead to reduced biomass yields and negative effects both on grasses and on the environment.
{"title":"Morphological and productivity responses of Buffel grass (Cenchrus ciliaris) and Guinea grass (Panicum maximum) ecotypes to simulated grazing in a semi-arid environment","authors":"Bosco Kidake Kisambo, Oliver V. Wasonga, Oscar K. Koech, George N. Karuku","doi":"10.1002/glr2.12033","DOIUrl":"10.1002/glr2.12033","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Livestock production is an economically significant activity in grassland-based production systems with herbivory, a critical process in modifying plant structure and regulating biomass dynamics in these areas.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A grazing simulation experiment was undertaken in a semi-arid environment in Kenya to determine the effects of clipping frequency and intensity on the morphology and productivity of <i>Cenchrus ciliaris</i> and <i>Panicum maximum</i> grass ecotypes. The ecotypes were clipped at different frequencies (every 2, 4, and 12 weeks) and different intensities (5, 10, and 15 cm clipping heights). The morphological responses of the grass ecotypes and biomass yields were determined.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The grass ecotypes showed significantly (<i>p</i> < 0.05) varied responses to cutting frequency and intensity. Morphological parameters, tillering, and biomass production were all affected by clipping frequency and intensity. The highest dry matter (DM) yields were recorded under low frequency (LF) clipping, followed by moderate frequency (MF) clipping and high frequency (HF) clipping. LF clipping in <i>C. ciliaris</i> ecotype Kilifi was 20% and 31% more compared to MF and HF clipping. No significant difference in yields was found by cutting the <i>C. ciliaris</i> ecotype Magadi at 4- and 12-week intervals, even though clipping at 2-week intervals cumulatively yielded less biomass. There was a biomass yield reduction in <i>P. maximum</i> ecotype Taveta of 23% and 25% for MF and HF clipping, respectively, while for ecotype Isinya, the reduction was 13% and 15% for MF and HF, respectively. Clipping intensity had a significant (<i>p</i> < 0.05) effect on cumulative yields in <i>C. ciliaris</i> ecotypes, but not <i>P. maximum</i>. Ecotypic differences were apparent in both <i>C. ciliaris</i> and <i>P. maximum</i> ecotype DM yields.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The results in this study suggest that clipping range grass ecotypes less frequently (4- and 12-week intervals) and at 10 and 15 cm stubble heights results in higher biomass yields. Generally, LF and MF grazing and cutting strategies are advantageous for semi-arid lands. Combinations of frequent and high-intensity utilization grazing strategies should be discouraged as they are likely to lead to reduced biomass yields and negative effects both on grasses and on the environment.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 4","pages":"290-300"},"PeriodicalIF":0.0,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74399323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qinyan Bao, Tezera W. Wolabu, Qian Zhang, Tian Zhang, Zhipeng Liu, Juan Sun, Zeng-Yu Wang
Genome editing is an advanced genetic modification tool that facilitates the removal, insertion, or substitution of nucleotides in the genome of an organism for mutation induction. CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) is the most widely used genome editing tool that can precisely modify the specific sequence of a genome. Significant progress has been made in the use of CRISPR/Cas9 for the genetic improvement of food crops. However, in forage crops, the use of CRISPR/Cas9 is still in the infant stage with limited understanding and application. This article reviews current advances in the establishment and application of the CRISPR/Cas9 system in alfalfa, summarizes the application of CRISPR/Cas9 in several other forage legume and grass species, and discusses the prospects of CRISPR/Cas9 in the genetic improvement of forage crops.
基因组编辑是一种先进的基因修饰工具，它促进了生物体基因组中核苷酸的去除、插入或替代，以诱导突变。CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9)是目前应用最广泛的基因组编辑工具，可以精确修饰基因组的特定序列。利用CRISPR/Cas9技术对粮食作物进行遗传改良已取得重大进展。然而，在饲料作物中，CRISPR/Cas9的使用仍处于起步阶段，了解和应用有限。本文综述了目前CRISPR/Cas9系统在苜蓿中的建立和应用进展，总结了CRISPR/Cas9在其他几种饲用豆科植物和禾草中的应用，并对CRISPR/Cas9在饲用作物遗传改良中的应用前景进行了展望。
{"title":"Application of CRISPR/Cas9 technology in forages","authors":"Qinyan Bao, Tezera W. Wolabu, Qian Zhang, Tian Zhang, Zhipeng Liu, Juan Sun, Zeng-Yu Wang","doi":"10.1002/glr2.12036","DOIUrl":"10.1002/glr2.12036","url":null,"abstract":"<p>Genome editing is an advanced genetic modification tool that facilitates the removal, insertion, or substitution of nucleotides in the genome of an organism for mutation induction. CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) is the most widely used genome editing tool that can precisely modify the specific sequence of a genome. Significant progress has been made in the use of CRISPR/Cas9 for the genetic improvement of food crops. However, in forage crops, the use of CRISPR/Cas9 is still in the infant stage with limited understanding and application. This article reviews current advances in the establishment and application of the CRISPR/Cas9 system in alfalfa, summarizes the application of CRISPR/Cas9 in several other forage legume and grass species, and discusses the prospects of CRISPR/Cas9 in the genetic improvement of forage crops.</p>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 4","pages":"244-251"},"PeriodicalIF":0.0,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12036","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85444277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system is a fast-growing, genome editing technology that has wide applications in identifying gene functions as well as improving agricultural production and crop breeding. Here, we summarized recent advances in the development and applications of genome editing technologies in plants. We briefly described CRISPR/Cas9 technology and examined the base and prime editing techniques that have been developed from CRISPR technology. Some new prime editing-derived techniques were assessed.
CRISPR /CRISPR相关蛋白9 (CRISPR -associated protein 9, Cas9)系统是一种快速发展的基因组编辑技术，在鉴定基因功能以及改善农业生产和作物育种方面有着广泛的应用。本文综述了近年来植物基因组编辑技术的发展和应用进展。我们简要介绍了CRISPR/Cas9技术，并研究了从CRISPR技术发展而来的碱基和引物编辑技术。评估了一些新的原始编辑衍生技术。
{"title":"Plant genome editing: CRISPR, base editing, prime editing, and beyond","authors":"Yujie Xie, Syed Inzimam Ul Haq, Xingyu Jiang, Dianfeng Zheng, Naijie Feng, Wenying Wang, Jin-Sheng He, Quan-Sheng Qiu","doi":"10.1002/glr2.12034","DOIUrl":"10.1002/glr2.12034","url":null,"abstract":"<p>The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system is a fast-growing, genome editing technology that has wide applications in identifying gene functions as well as improving agricultural production and crop breeding. Here, we summarized recent advances in the development and applications of genome editing technologies in plants. We briefly described CRISPR/Cas9 technology and examined the base and prime editing techniques that have been developed from CRISPR technology. Some new prime editing-derived techniques were assessed.</p>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 4","pages":"234-243"},"PeriodicalIF":0.0,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87016792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chen, A. A., Fei, S.-z., Lenssen, A. W., & Moore, K. J. (2022). Photothermal controls of vegetative dormancy in Poa secunda. Grassland Research, 1(1), 43–52. https://doi.org/10.1002/glr2.12008
There is an error in Figure 5. The image for Figure 5a is identical to Figure 5c. The corrected Figure 5 is shown below.
We apologize for this error.
陈，A. A.，费，s -z。， Lenssen, a.w.， &;Moore, K. J.(2022)。光热控制下白豌豆营养休眠。草地研究，1(1)，43-52。https://doi.org/10.1002/glr2.12008There在图5中是一个错误。图5a的图像与图5c相同。更正后的图5如下所示。我们为这个错误道歉。
{"title":"Correction to Photothermal controls of vegetative dormancy in Poa secunda","authors":"","doi":"10.1002/glr2.12031","DOIUrl":"https://doi.org/10.1002/glr2.12031","url":null,"abstract":"<p>Chen, A. A., Fei, S.-z., Lenssen, A. W., & Moore, K. J. (2022). Photothermal controls of vegetative dormancy in <i>Poa secunda</i>. <i>Grassland Research</i>, <i>1</i>(1), 43–52. https://doi.org/10.1002/glr2.12008</p><p>There is an error in Figure 5. The image for Figure 5a is identical to Figure 5c. The corrected Figure 5 is shown below.</p><p>We apologize for this error.</p>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 4","pages":"279"},"PeriodicalIF":0.0,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137942243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Onion grass (Romulea rosea) is a common weed that infests native and improved pastures in the Mediterranean environments of southern Australia. It is a very challenging weed to control due to its distinctive growth and survival mechanisms involving corms.
Methods
Three glasshouse experiments were conducted in Australia to investigate the response of onion grass to defoliation and fertiliser application, the development and growth of onion grass corms and the chemical control of the weed in winter and spring.
Results
Defoliating consistently to 1 cm above ground reduced corm weight by 84% compared with the control. Medium or high fertiliser application did not increase herbage mass of onion grass compared with the nonfertilised treatment. The corm weight of onion grass declined from Weeks 1 to 8 after emergence, remained at 53–60 mg dry matter (DM) corm−1 from Weeks 8 to 19 and then declined on average to 37 mg DM corm−1 up to Week 26 after emergence. New corms started to develop at Week 6 after emergence. A small proportion of the onion grass plants (7.5%) developed multiple new corms (3–6 corms) from a single old corm. The most effective herbicide control was a winter application of metsulfuron methyl or imazamox as an alternative product to protect clover.
Conclusions
This study has identified the growth and development patterns of onion grass corms, how the plant responded to defoliation and fertiliser application and effective chemical control of this weed. These findings have significant practical implications for the improvement of onion grass-infested pastures.
{"title":"Responses to defoliation and fertiliser, corm development and chemical control of onion grass (Romulea rosea) in the Mediterranean environment of southern Australia","authors":"Zhongnan Nie, Reto Zollinger, Ralph Behrendt","doi":"10.1002/glr2.12030","DOIUrl":"10.1002/glr2.12030","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Onion grass (<i>Romulea rosea</i>) is a common weed that infests native and improved pastures in the Mediterranean environments of southern Australia. It is a very challenging weed to control due to its distinctive growth and survival mechanisms involving corms.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Three glasshouse experiments were conducted in Australia to investigate the response of onion grass to defoliation and fertiliser application, the development and growth of onion grass corms and the chemical control of the weed in winter and spring.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Defoliating consistently to 1 cm above ground reduced corm weight by 84% compared with the control. Medium or high fertiliser application did not increase herbage mass of onion grass compared with the nonfertilised treatment. The corm weight of onion grass declined from Weeks 1 to 8 after emergence, remained at 53–60 mg dry matter (DM) corm<sup>−1</sup> from Weeks 8 to 19 and then declined on average to 37 mg DM corm<sup>−1</sup> up to Week 26 after emergence. New corms started to develop at Week 6 after emergence. A small proportion of the onion grass plants (7.5%) developed multiple new corms (3–6 corms) from a single old corm. The most effective herbicide control was a winter application of metsulfuron methyl or imazamox as an alternative product to protect clover.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study has identified the growth and development patterns of onion grass corms, how the plant responded to defoliation and fertiliser application and effective chemical control of this weed. These findings have significant practical implications for the improvement of onion grass-infested pastures.</p>\u0000 </section>\u0000 </div>","PeriodicalId":100593,"journal":{"name":"Grassland Research","volume":"1 3","pages":"197-206"},"PeriodicalIF":0.0,"publicationDate":"2022-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/glr2.12030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82592220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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