Frontiers in Plant Science最新文献

Faba bean (Vicia faba L.) is an important pulse crop traditionally used for human nutrition and animal feeding. With a high protein content ranging from 24% to 35% of seed dry matter, considerable amounts of globulins, essential amino acids and minerals, faba bean is today an important source meeting the growing global demand for nutritious food. The objective of study was to investigate the variability of nine phenological, phenotypical and yield related traits in 220 faba bean accessions in multi-location trials across four representative European regions. Nine field trials were carried out from 2018 till 2020 in four representative European locations (Spain, Finland, Belgium and Serbia) using an augmented p-rep design containing 20 replicated checks. Significant differences among genotypes and environments were detected, being the genotype x environment interaction (GEI) the major source of variation in five of the nine evaluated traits. The "which-won-where" analyses identified two mega-environment namely South European mega environment (SE-ME) and North European mega environment (NE-ME), while the best performing and most stable genotypes according to the nine traits were identified using "means vs stability" analyses. According to the highest trait value in each mega environment several winning genotypes were identified showing better performances than some commercial varieties (controls) or checks. Our results suggest that the geographical locations falling into each mega-environment can be used as faba bean test locations. The genotype ranking for the multi-trait stability index (MTSI) revealed that the most stable and best ranking genotypes in SE-ME are G018, G086, G081, G170 and G015 while in the north mega-environment are G091, G171, G177 (Merkur), G029 and G027. Hierarchical cluster analysis and principal component analyses showed a clear correlation between the traits analysed and the botanical type. These findings indicate that botanical type is one of the most significant factors affecting development in any environment, and it must be taken into account in faba bean breeding activities. The information derived from this study provides a chance for breeding new resilient faba bean cultivars adapted to different agroecological European regions, a critical point for addressing Europe's reliance on protein imports and enhancing sustainable agriculture practices.

In the North China Plain, it is common for farmers to regularly clear crop residues from their fields. The prevalent practice of fertilization in this region continues to depend heavily on the use of compound fertilizers. Howere , long-term single fertilizer application has become the norm in the present agricultural production, which not only destroys the crop rotation system but also negatively affects the soil environment and crop yields. The current knowledge of how nutrient deficits affect the microbial community structure in double-cropping systems is still limited. To clarify the specific response of soil microorganisms to the absence of key nutrients in the ecosystems of the annual double cropping system, this study investigated how the lack of essential nutrients affected the diversity, abundance, and functional dynamics of microorganisms in the soil, and designed five treatment methods: (1) CK, nofertilizer treatment; (2) NPK, adequate nitrogen fertilizer, phosphorus fertilizer, and potassium fertilizer treatment; (3) PK, nitrogen deficiency treatment; (4) NK, phosphorus deficiency treatment; and (5) NP, potassium deficiency treatment. The results showed that in two growing seasons, NPK treatment increased the yields of wheat and corn by 16.9% and 27.0%, respectively, while NK and NP treatments increased by 13.4%, 5.4%, 25.0%, and 17.9%, respectively, and the total annual yield increased by 21.1%. In addition, NPK treatment promoted the microbial diversity and abundance of wheat and maize, and balanced fertilization provided more comprehensive nutritional support for crops. Compared to other nutrient-deficient treatments, NPK treatment substantially increased the abundance and functional diversity of soil bacterial and fungal communities (p<0.05). The structure and abundance of soil microbial communities are significantly correlated with soil physicochemical factors that involve organic matter, pH, potassium content, phosphorus, and nitrogen levels. pH is the primary environmental factor influencing the diversity of soil microbial communities.

Water scarcity and labor shortage pose significant challenges in rice farming. Direct-seeded rice (DSR) is an efficient method that conserves water, reduces labor costs, and allows for full mechanization of cultivation. However, variable planting depth in undulated field leading to deep/shallow sowing of rice seeds during mechanical sowing presents a major hurdle, as existing varieties lack tolerance to deep sowing. To address this, a mapping population comprising 150 F₄ lines, derived from MTU 1010 and AUS295, was developed and phenotyped for emergence from deep soil depth-related traits, including days of emergence (DE), percent germination (PG), mesocotyl length (ML), and coleoptile length (CL). The correlation revealed that DE has a significant negative correlation with PG, ML, and CL, whereas PG, ML, and CL are all positively correlated with each other. The mapping population was genotyped with mid-density SNP assay (1k-RiCA), and a linkage map was established with 414 polymorphic SNP markers. A total of 16 QTLs were identified for four traits, with phenotypic variance explained (PVE) ranging from 6.63% to 19.6% in the WS22. These included 5 QTLs for DE, 3 QTLs for PG, 4 QTLs for ML, and 4 QTLs for CL. Out of 16 QTLs identified, 12 were major effect QTLs (qDE_1.2 , qDE_1.3 , qDE_1.4 , qDE_2.1 , qDE₁₂ , qPG_2.1, qPG_2.2, qML_2.1, qML_2.2 , qCL₁ , qCL_2.2, qCL_2.3 ) and 4 were minor effect QTLs (qPG₁, qML_1.2, qCL_2.1 ). During DS23 season, QTL analysis for DE and PG traits identified seven and three QTLs, respectively. Out of the ten QTLs identified in DS23 season, eight were stable across the season. This study reported 11 novel QTLs, while 7 had been previously reported. The study pinpointed three QTL hotspot regions: one on chromosome 1 (qPG₁ , qCL₁ ) and two on chromosome 2 (qPG_2.1, qML_2.2, qCL_2.1 ) and (qPG_2.2, qCL_2.2 ). Candidate gene analysis in the identified QTL regions found two genes associated with hormonal pathways: OsSLR1 for gibberellin signaling and OsSAUR11 for abscisic acid signaling. Additionally, one gene (OsMT3a) associated with early seedling vigor and another (OsABA8ox1) regulates germination through coleoptile growth. The identified QTLs, genes, and breeding lines from this study provide valuable resources for developing rice varieties with enhanced tolerance to deep soil emergence, making them well-suited for mechanized DSR systems.

Early fruit size prediction in greenhouse tomato (Solanum lycopersicum L.) is crucial for growers managing cultivars to reduce the yield ratio of small-sized fruit and for stakeholders in the horticultural supply chain. We aimed to develop a method for early prediction of tomato fruit size at harvest with machine learning algorithm, and three machine learning models (Ridge Regression, Extra Tree Regrreion, CatBoost Regression) were compared using the PyCaret package for Python. For constructing the models, the fruit weight estimated from the fruit diameter obtained over time for each cumulative temperature after anthesis was used as explanatory variable and the fruit weight at harvest was used as objective variable. Datasets for two different prediction periods after anthesis of three tomato cultivars ("CF Momotaro York," "Zayda," and "Adventure.") were used to develop tomato size prediction models, and their performance was evaluated. We also aimed to improve the model adding the average temperature during the prediction period as an explanatory variable. When the estimated fruit size data at cumulative temperatures of 200°C d, 300°C d, and 500°C d after anthesis were used as explanatory variables, the mean absolute percentage error (MAPE) was lowest for "Zayda," a cultivar with stable fruit diameter, at 9.8% for Ridge Regression. When the estimated fruit size at cumulative temperatures of 300°C d, 500°C d, and 800°C d after anthesis were used as explanatory variables for Ridge Regression, the MAPE decreased for all cultivars: 10.1% for "CF Momotaro York," 8.8% for "Zayda," and 10.0% for "Adventure." In addition, incorporating the average temperature during the fruit size prediction period as an explanatory variable slightly increased model performance. These results indicate that this method could effectively predict tomato size at harvest in three cultivars. If fruit diameter data acquisition could be automated or simplified, it would assist in cultivation management, such as tomato thinning.

The aggravation of ozone (O₃) pollution poses a significant threat to agricultural production. With China being the leading wheat producer of the world, contributing 17.8% to global output, the vulnerability of wheat to O₃ is of particular concern. Despite extensive research on the impacts of O₃ on wheat production and the ongoing development of new wheat cultivars over the years, a connection between yield loss and the released ages of wheat cultivars under O₃ stress remains unestablished. Addressing this, the experiment was carried out at the Yangzhou Rice and Wheat Free-air Gas Concentration Enrichment (FACE) Testing Base in China, using 17 wheat cultivars developed since the 1970s as experimental materials. The elevated O₃ concentration in the test was 1.5 times higher than that in a normal atmosphere. The results indicated that O₃ led to a significant reduction in wheat yield of 18.19%. The yield of cultivars released in the 1970s, 1980s, 1990s, and after 2000, decreased by 24.9%, 23.3%, 19.8%, and 14.7%, respectively. Overall, the direct effect of 1,000-grain weight on yield was the most significant, followed by the number of grains per spike, whereas the number of spikes contributed least to the yield components. To enhance resistance to O₃ stress in future breeding efforts, increasing the 1,000-grain weight should be a primary objective. Our findings also revealed that elevated O₃ concentration led to higher sedimentation values and protein content while lowering bulk density, hardness, and starch content. As the release age approaches, the rate of decrease in bulk density diminishes gradually. In terms of hardness, sedimentation value, and starch content, varieties released in the 1990s exhibited less sensitivity, whereas those released after the 2000s experienced the most significant changes in protein content. It is worth noting that the impact on the nutritional quality of modern cultivars is particularly significant, particularly regarding starch and protein content. Stress indices indicate that the cultivars released after 2000 exhibit stronger resistance to yield loss. The Yangmai series cultivars appear to be promising parental lines for future breeding programs aimed at developing O₃-resistant wheat.

Thrips are one of the most challenging pests in agricultural crops, including Chrysanthemum. In this study we tested via two plant assays whether solutions containing sticky rice germ oil (RGO) droplets could effectively trap thrips and lower thrips damage on Chrysanthemum. In the first assay, we additionally assessed the metabolomic effects of these RGO droplet sprays and thrips presence on plant chemistry via ¹H NMR and headspace GC-MS on multiple timepoints to investigate which plant metabolites were affected by spraying and their potential relation to plant resistance against thrips. In the second assay, we tested the individual RGO solution constituents against thrips. Our results suggested that the adhesive RGO droplets were not effective as a physical trap as only three out of 600 adult thrips were caught at the achieved coverage. However, average thrips damage was still reduced up to 50% and no negative effects on plant growth were observed up to 25 days. Results from the second plant assay indicated that the individual constituents of the solution containing RGO droplets may have direct effects against thrips. Metabolomics analysis of sprayed leaves via headspace GC-MS and ¹H NMR indicated that fatty acids and several volatile compounds such as 4(10)-thujene (sabinene), eucalyptol, cis-4-thujanol, and isocaryophyllene were highest on day 10, while sucrose, malic acid, o-Cymene, and 3-Methyl-2-butenoic acid were highest on day 25. Plants with thrips showed higher flavonoid, carbohydrate and glutamine acetic acid levels, and lower fatty acids and malic acid levels. RGO application increased the levels of fatty acids and alcohols present on top of and inside the Chrysanthemum leaves, while decreasing the concentrations of volatile compounds such as eucalyptol, chrysanthenone and eugenol in the Chrysanthemum leaves. Most interestingly, the thrips effect on the plant metabolome was no longer visible in RGO treated plants at the later harvesttime, suggesting that RGO application may overrule or prevent the metabolomic effects of thrips infestation. In conclusion, our study provides new information on how the application of a new plant-based plant protection product affects insect herbivores and alters crop phytochemistry for improved herbivore resistance.

Ovule number per ovary (ONPO) determines the maximum potential of seed number per fruit that is a direct component of seed yield in crops. This study aimed to dissect the genetic basis and molecular mechanism of ONPO using a newly developed doubled haploid (DH) population in oilseed rape. In all the four investigated environments, the ONPO of 201 DH lines exhibited normal distribution with a wide variation from 22.6 to 41.8, suggesting quantitative inheritance appropriate for mapping QTL. A skeleton genetic map of 2111 markers within 19 linkage groups was developed, with a total of 1715.71 cM in length and an average of 0.82 cM between markers. Linkage mapping identified ten QTLs that were distributed on eight chromosomes and explained 7.0-15.9% of the phenotypic variance. Among these, four were identical to the reported and two were repeatedly detected with relatively large effects, highlighting their potential for marker-assisted selection. Phytohormone quantification of ovaries (at the ovule initiation stage) from two pools of high and low ONPO lines showed significant differences in the levels of nine sub-types of phytohormones, suggesting their important roles in regulating ovule number. Transcriptomic analysis identified 7689 differentially expressed genes (DEGs) between the two pools, of which nearly half were enriched into functional categories of reported genes regulating ONPO, including protein, RNA, signalling, miscellaneous, development, hormone metabolism, and tetrapyrrole synthesis. Integration of linkage QTL mapping, transcriptome sequencing and BLAST analysis identified 15 homologues of reported ovule number genes and 327 DEGs in the QTL regions, which were considered as direct and potential candidate genes. These findings propose further insights into the genetic basis and molecular mechanisms of ONPO, which will facilitate future gene cloning and genetic improvement for enhancing seed yield in oilseed rape.

Light and nitrogen are crucial environmental factors that significantly impact rice growth and quality formation. Currently, there is a lack of systematic research on how light and nitrogen affect carbon and nitrogen metabolism during grain filling, subsequently affecting the eating quality of rice. To address this gap, field experiments were conducted under varying light intensities and nitrogen fertilizer levels to investigate the changes in carbon and nitrogen metabolism during grain filling, the eating quality of rice at maturity, and the relationship between them. The findings revealed that, 50% light intensity suppressed carbon metabolism while stimulating nitrogen metabolism, resulting in a reduction in the C/N ratio, decreased starch content by 4.30% to 5.59%, and elevated protein content by 21.31% to 29.70%, thereby leading to decreased rice eating quality by 10.06% to 11.42%. Conversely, the application of panicle fertilizer boosted nitrogen metabolism while hindering carbon metabolism, leading to a decrease in the C/N ratio, increased protein content by 21.31% to 29.70%, and reduced starch content by1.60% to 2.93%, thereby leading to decreased rice eating quality by 4.13% to 6.71%. Correlation analysis revealed a significant positive correlation between the C/N ratio and carbon metabolism-related enzyme activities and products, along with a significant negative correlation with nitrogen metabolism-related enzyme activities and products, suggesting that the C/N ratio can serve as an indicator of carbon and nitrogen metabolism levels. Further analysis revealed a significant positive relationship between the C/N ratio and taste value, indicating that higher levels of carbon metabolism promote the development of good rice eating quality, while nitrogen metabolism exerts an opposing influence. In summary, notable variances in carbon and nitrogen metabolism were observed within the same japonica rice cultivar under diverse light and nitrogen fertilizer conditions. These metabolic differences impact the synthesis of starch and protein in the endosperm, ultimately influencing rice quality. Our study contributes to a more profound comprehension of the regulation of carbon and nitrogen metabolism in rice by light and nitrogen fertilizer, as well as their role in determining eating quality.