Late sowing is one of the primary factors restricting wheat production in the middle and lower reaches of the Yangtze River. Cultivating late-sowing-tolerant wheat varieties can effectively mitigate 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 results 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 significantly 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 Yangmai 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 maturity. 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 booting to anthesis. The former helped accumulate more thermal and solar resources during the productive tillering phase, while the latter provided more time and more thermal and solar resources for floret 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.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |