耐晚播小麦品种的产量构成、器官发育及温光资源利用特征OA

Late sowing is one of the primary factors restricting wheat production in the middle and low-er reaches of the Yangtze River.Cultivating late-sowing-tolerant wheat varieties can effectively miti-gate yield losses due to delayed sowing.To elucidate the characteristics of late-sowing-tolerant wheat varieties,this experiment compared grain yield and its components,organ development processes,and the utilization of thermal and solar resources among four wheat varieties of Yangmai 25,Yangmai 28,Yangmai 30,and Yangmai 39 under late-sowing pattern with increased planting density.The re-sults indicated that delaying the sowing date led to a significant reduction in grain number and grain yield.Under late-sowing conditions,Yangmai 25 and Yangmai 30 exhibited significantly higher grain yields,primarily attributed to their greater spike numbers.Furthermore,Yangmai 30 exhibited sig-nificantly more grains per spike.Under late-sowing pattern with increased planting density,tiller number decreased,while tiller fertility increased significantly.Yangmai 25 exhibited significantly more tillers developed in spring season compared with other varieties,while Yangmai 30 exhibited higher tiller fertility.Although late sowing reduced leaf age and tiller number,Yangmai 25 and Yang-mai 30 showed relatively faster leaf age progression and greater total tiller number.Meanwhile,late sowing significantly shortened the period from tillering to jointing and the period from anthesis to ma-turity.This might be unfavorable for the occurrence of tillering and the filling of grains.Among the four varieties,Yangmai 25 showed an earlier jointing stage and a prolonged duration from jointing to booting,whereas Yangmai 30 exhibited an earlier booting stage and a prolonged duration from boo-ting to anthesis.The former helped accumulate more thermal and solar resources during the produc-tive tillering phase,while the latter provided more time and more thermal and solar resources for flo-ret differentiation.In conclusion,the late-sowing-tolerant varieties,Yangmai 25 and Yangmai 30,share key adaptive traits:accelerated tillering-phase development with efficient temperature and solar radiation resource capture,concomitantly with prolonged process during the productive tillering phase and sufficient accumulation of temperature and solar radiation.