DataSheet_1_Field assessment of yield and its contributing traits in cowpea treated with lower, intermediate, and higher doses of gamma rays and sodium azide.docx

Across the globe, plant breeders of different organizations are working in collaboration to bring preferred traits to crops of economic importance. Among the traits, “high yielding potential” is the most important as it is directly associated with food security and nutrition, one of the sustainable development goals. The Food and Agriculture Organization acknowledges plant breeders’ role and efforts in achieving local and global food security and nutrition. Recognizing the importance of pulses and increasing pressure on food security, the United Nations General Assembly declared 2016 the “International year of Pulses” owing to their preferred traits such as climate change resilience, wide adaptability, low agriculture input, and protein- and nutrient-rich crops. Keeping all these developments in consideration, we initiated an induced mutagenesis program by treating cowpea (Vigna unguiculata L. Walp.) with different doses of gamma rays and sodium azide aiming to enhance the yielding potential of an otherwise outstanding variety viz., Gomati VU-89 and Pusa-578. We noticed a substantial increase in mean values of agronomic traits in putative mutants raised from seeds treated with lower and intermediate doses of mutagens. Statistical analysis such as correlation, path, hierarchical clustering analysis (HCA), and principal component analysis (PCA) were used to assess the difference between mutagenized and control populations. A significant and positive correlation of yield with yield-attributing traits was recorded. However, among all the yield attributing traits, seeds per pod (SPP) depicted the maximum direct impact upon yield, and therefore, working on this trait may yield better results. A widely used PCA revealed 40.46% and 33.47% of the total variation for var. Gomati VU-89 and var. Pusa-578, respectively. Cluster analysis clustered treated and control populations into separate clusters with variable cluster sizes. Cluster V in the variety Gomati VU-89 and cluster V and VI in the variety Pusa 578 comprised of putative mutants were higher yielding and hence could be recommended for selection in future breeding programs. We expect to release such mutant lines for farmer cultivation in Northern parts of India depending on the performance of such high-yielding mutant lines at multilocations.

全球范围内，各机构的植物育种工作者正协同合作，为经济作物导入优良性状。在各类性状中，"高产潜力"最为关键，因其直接关乎粮食安全与营养供给，而这正是可持续发展目标的核心内容之一。联合国粮食及农业组织（Food and Agriculture Organization，FAO）肯定了植物育种者在实现本地及全球粮食安全与营养保障过程中所发挥的作用与付出的努力。鉴于食用豆类（pulses）的重要性日益凸显，以及粮食安全面临的压力不断增大，联合国大会将2016年定为"国际食用豆类年"，这是因为食用豆类具备诸多优良性状：如气候变化韧性强、适应范围广、农业投入需求低，且作物本身富含蛋白质与营养物质。鉴此，本研究启动了诱导诱变育种项目：以不同剂量的γ射线（gamma rays）与叠氮化钠（sodium azide）处理豇豆（Vigna unguiculata L. Walp.），旨在提升现有优良品种"Gomati VU-89"与"Pusa-578"的高产潜力。研究发现，经低剂量与中剂量诱变剂处理后的种子培育出的推定突变体，其农艺性状的均值均有显著提升。本研究采用相关性分析、通径分析、系统聚类分析（Hierarchical Clustering Analysis，HCA）以及主成分分析（Principal Component Analysis，PCA）等统计方法，对诱变群体与对照群体间的差异进行评估。研究结果显示，籽粒产量与产量构成性状间存在显著正相关关系。但在所有产量构成性状中，每荚粒数（SPP）对产量的直接影响最大，因此针对该性状开展育种工作有望获得更佳效果。主流的主成分分析结果显示，对于品种"Gomati VU-89"与"Pusa-578"，其总变异的解释率分别为40.46%与33.47%。系统聚类分析将诱变群体与对照群体划分为不同的簇，且各簇的规模存在差异。"Gomati VU-89"的第V簇，以及"Pusa-578"的第V簇与第VI簇均由推定突变体组成，且这些簇内的材料产量更高，因此可推荐用于未来育种项目中的选育工作。本研究期望根据这些高产突变株系在多地点的试验表现，将其推广至印度北部地区供农户种植。