To understand the compensatory effect of the germination and earing of latent axillary buds in wheat on yield after late spring cold stress, artificial intelligence greenhouses were used to simulate late spring coldness by applying freezing stress of different durations to wheat plants at different panicle development stages. Combined with different topdressing nitrogen levels, the changes in the germination and growth characteristics of wheat axillary buds and their effects on yield after late spring coldness were analyzed. The results showed that freezing stress at both the anther septum formation stage and the tetrad stage promoted the germination and growth of latent axillary buds in wheat, and the number of germinated axillary buds and their growth rate increased with the extension of stress duration and the increase of topdressing nitrogen amount. Compared with the main stem, the growth of regenerated tillers (formed by the germination and elongation of axillary buds) after freezing stress was significantly reduced: plant height, stem diameter, number of leaves, leaf area, and aboveground dry matter at the flowering stage and maturity stage decreased by 40.67%, 24.51%, 54.55%, 54.15%, 67.33%, and 63.69%, respectively. The panicle distribution ratio and post-anthesis dry matter contribution rate of regenerated tillers at the flowering stage and maturity stage increased by 101.59%, 11.06%, and 13.75%, respectively. The regenerated panicles (formed by regenerated tillers) had a smaller panicle shape, with panicle length, number of spikelets per spike, number of grains per panicle, 1 000-grain weight, and yield per panicle decreasing by 22.71%, 14.86%, 49.51%, 20.05%, and 59.50%, respectively. The later the stress occurred, the smaller the growth and panicle shape of regenerated tillers; however, the growth and panicle shape increased with the extension of stress duration and the increase of topdressing nitrogen amount. The earing rate of regenerated tillers under different treatments ranged from 32.52% to 66.35%, and the compensatory effect on yield loss ranged from 12.06% to 70.89%. Overall, the more severe the stress, and the higher the topdressing nitrogen amount, the higher the earing rate of regenerated tillers and their compensatory effect on yield. In conclusion, although the regenerated tillers produced after late spring coldness have small growth, they have a high harvest index and a significant compensatory effect on yield loss, and sufficient nutrient supply is an important guarantee for improving the availability of regenerated tillers.
| 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 |