关键词: 无芒隐子草, 光合速率, 叶重量, 叶位, 种子产量, 相关分析

Abstract:

Field trial was conducted to investigate the photosynthetic rate and biomass of leaves at different positions during seed development of Cleistogenes songorica, a widely spread native grass species that has potential to be used as forage crop and trufgrass in arid and semi-arid regions of northwest China. Meanwhile, correlation analysis was carried out between seed yield and photosynthetic performance and biomass of leaves at different positions during seed development. The results showed that photosynthetic rate, biomass and water content of leaves at the same position significantly decreased during seed development, in the same seed development stage, there were also significantly different in photosynthetic rate, biomass and water content of leaves at different positions. Photosynthetic contribution of leaves at positions 1~4 showed a significantly increase during seed development, while significantly decreases were observed at positions 5~7. With the decline of leaf position, photosynthetic contribution increased first, and then descended significantly, regardless of the seed development stage. Total leaf biomass was significantly decreased with the development of seed, while spikelet biomass showed an adverse trend. There was a positive correlation between seed yield and photosynthetic rate and biomass of leaves at positions 1~5 before milk stage, while photosynthetic rate and biomass of leaves at position 6 positively correlated with seed yield only at peak flowering stage, furthermore, these data of leaves at position 7 showed negative correlation with seed yield during the entire seed development period. Total leaf biomass positively correlated with seed yield at peak flowering stage and seed filling stage, while negatively at other stages, on the contrary, negative correlation was observed between spikelet biomass and seed yield at peak flowering stage, yet positive correlation were obtained at subsequent stages. In conclusion, leaves at positions 1~5 were pivotal for C. songorica seed production, especially from peak flowering stage to milk stage.

Key words: Cleistogenes songorica, Photosynthesis, Leaf biomass, Leaf position, Seed yield, Correlation analysis