Timely sowing of wheat (Triticum aestivum L.) is a crucial agronomic measure to realize its genetic yield potential, particularly under ever‐changing climatic conditions. The present study appraised the genotypic variations of wheat genotypes for dry matter and nutrients' accumulation, partitioning, remobilization and stress indices under timely and late sown conditions of irrigated semi‐arid ecology. Five potential wheat genotypes viz. HD‐2967, HD‐3086, HD‐3249, DBW‐187 and HD‐3226 were evaluated under field conditions, however, the studies for root‐system traits were made in PVC tubes. Timely sown wheat had grain yield advantage of 18%, and genotypes DBW‐187 (5.77 t ha−1) and HD‐2967 (4.78 t ha−1) produced the highest grain yield under the timely and late sown conditions respectively. The days (d) to anthesis and grain filling period under the late sown was hastened by 5.2 d, and shortened by 7.4 d. Timely sowing enhanced the post‐anthesis dry matter accumulation and remobilization to the tune of 18.8% and 23% respectively. Nitrogen, phosphorus and potassium accumulated post‐anthesis and their remobilization under the timely sown was significantly greater than the late sown, while the contribution of remobilization to grain content was higher under the late sown except for the nitrogen. The canopy temperature was cooler by 2°C under the timely sown, while the canopy temperature depression was greater by 0.8–1.04°C, at anthesis and dough stages of the crop. The leaf chlorophyll content (SPAD meter value) at anthesis and dough stages improved by 10% and 7.6% due to timely sowing. The genotypes HD‐2967 and HD‐3249 had relatively greater geometric mean productivity and stress tolerance index coupled with a comparatively higher yield stability index. Further, the root‐system traits, that is, total root length (TRL), root biomass and root length density (RLD) were significantly superior both at 50 DAS (days after sowing) and at anthesis under the timely sown compared to the late sown. This study clearly outlined that timely sowing of wheat resulted in higher post‐anthesis dry matter accumulation, nutrient acquisition and remobilization along with improved root‐system traits and grain yield. Screening of the genotypes, based on stress indices would result in a better understanding of the genotypic performance and improve the genetic yield potential under varying environmental conditions.

中文翻译：

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晚播胁迫影响花后干物质和养分分配及其在普通小麦基因型中的再利用

适时播种小麦（小麦L.) 是实现其遗传产量潜力的一项重要农艺措施，特别是在不断变化的气候条件下。本研究评估了灌溉半干旱生态适时和晚播条件下小麦基因型干物质和养分积累、分配、再利用和胁迫指数的基因型变异。五种潜在的小麦基因型即。 HD-2967、HD-3086、HD-3249、DBW-187 和 HD-3226 在田间条件下进行了评估，但根系性状的研究是在 PVC 管中进行的。适时播种的小麦产量优势为 18%，基因型 DBW-187（5.77 吨公顷）−1）和 HD-2967（4.78 吨公顷−1）分别在适时和晚播条件下产量最高。晚播下至花期和灌浆期的天数(d)提前了5.2 d，缩短了7.4 d。适时播种使花后干物质积累和再利用分别提高了18.8%和23%。氮、磷、钾在花后积累，且及时播下的再利用显着大于晚播，且除氮外，再利用对籽粒含量的贡献高于晚播。适时播种冠层温度降低2℃，花期、面团期冠层温度降低0.8～1.04℃。由于适时播种，花期和面团期叶片叶绿素含量（SPAD米值）分别提高了10%和7.6%。基因型HD-2967和HD-3249具有较高的几何平均生产力和抗逆指数，以及较高的产量稳定性指数。此外，及时播种的根系性状，即根总长度（TRL）、根生物量和根长度密度（RLD）在50 DAS（播种后天）和开花时均显着优于晚期播种。播种。这项研究明确指出，及时播种小麦可以提高花后干物质的积累、养分的获取和再利用，同时改善根系性状和谷物产量。基于胁迫指数的基因型筛选将有助于更好地了解基因型表现并提高不同环境条件下的遗传产量潜力。