Patidar Anil, Yadav Mahesh C, Kumari Jyoti, Tiwari Shailesh, Chawla Gautam, Paul Vijay
Division of Genomic Resources, Indian Council of Agricultural Research (ICAR)-National Bureau of Plant Genetic Resources, New Delhi 110012, India.
Post-Graduate School, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India.
Plants (Basel). 2023 Aug 2;12(15):2851. doi: 10.3390/plants12152851.
Bread wheat ( L.) is widely grown in sub-tropical and tropical areas and, as such, it is exposed to heatstress especially during the grain filling period (GFP). Global warming has further affected its production and productivity in these heat-stressed environments. We examined the effects of heatstress on 18 morpho-physiological and yield-related traits in 96 bread wheat accessions. Heat stress decreased crop growth and GFP, and consequently reduced morphological and yield-related traits in the delayed sown crop. A low heat susceptibility index and high yield stability were used for selecting tolerant accessions. Under heatstress, the days to 50% anthesis, flag-leaf area, chlorophyll content, normalized difference vegetation index (NDVI), thousand grain weight (TGW), harvest index and grain yield were significantly reduced both in tolerant and susceptible accessions. The reduction was severe in susceptible accessions (48.2% grain yield reduction in IC277741). The plant height, peduncle length and spike length showeda significant reduction in susceptible accessions, but a non-significant reduction in the tolerant accessions under the heatstress. The physiological traits like the canopy temperature depression (CTD), plant waxiness and leaf rolling were increased in tolerant accessions under heatstress. Scanning electron microscopy of matured wheat grains revealed ultrastructural changes in endosperm and aleurone cells due to heat stress. The reduction in size and density of large starch granules is the major cause of the yield and TGW decrease in the heat-stress-susceptible accessions. The most stable and high-yielding accessions, namely, IC566223, IC128454, IC335792, EC576707, IC535176, IC529207, IC446713 and IC416019 were identified as the climate-smart germplasm lines. We selected germplasm lines possessing desirable traits as potential parents for the development of bi-parent and multi-parent mapping populations.
普通小麦（Triticum aestivum L.）广泛种植于亚热带和热带地区，因此，尤其是在灌浆期（GFP）会遭受热胁迫。全球变暖进一步影响了其在这些热胁迫环境中的产量和生产力。我们研究了热胁迫对96份普通小麦材料的18个形态生理和产量相关性状的影响。热胁迫降低了作物生长和灌浆期，从而降低了晚播作物的形态和产量相关性状。利用低热敏感性指数和高产量稳定性来筛选耐性材料。在热胁迫下，无论是耐性材料还是敏感材料，抽穗50%的天数、旗叶面积、叶绿素含量、归一化植被指数（NDVI）、千粒重（TGW）、收获指数和籽粒产量均显著降低。敏感材料的降幅更为严重（IC277741的籽粒产量降低了48.2%）。在热胁迫下，敏感材料的株高、穗下节间长度和穗长显著降低，而耐性材料则无显著降低。热胁迫下，耐性材料的冠层温度降低（CTD）、植株蜡质和叶片卷曲等生理性状增加。成熟小麦籽粒的扫描电子显微镜观察显示，热胁迫导致胚乳和糊粉层细胞的超微结构发生变化。大淀粉粒大小和密度的降低是热胁迫敏感材料产量和千粒重下降的主要原因。确定了最稳定和高产的材料，即IC566223、IC128454、IC335792、EC576707、IC535176、IC529207、IC446713和IC416019为气候智能型种质系。我们选择了具有理想性状的种质系作为双亲和多亲作图群体发展的潜在亲本。
