关键词: 光周期, 糜子, 内源激素, 株高, 净光合速率, 籽粒蛋白质含量

Abstract:

【Objective】In this study, the variation law of photoperiod on physiology and ecology index of broomcorn millet were observed, which would facilitate to develop the genetic regulation network and map related genes of photoperiod.【Method】The experiments were conducted using 3 broomcorn millet varieties (N1-light insensitive-Neimi 1, N2-light middle-Neimi 2, and N3-light sensitive-Ningmi 14) with different light insensitive degree and with four photoperiod treatments in the pot. The phenological period was investigated. The endogenous hormone content at heading stage, plant height and grain protein content at mature period, and net photosynthetic rate of light insensitive variety after heading were measured.【Result】The growth period and plant height of broomcorn millet were significantly increase by long day compared with short day, which in light sensitive material N3 was 62.07% and 104.24% higher than that of short day, and light insensitive material N1 was 3.51% and 33.35%, respectively. The net photosynthetic rate of leaves after heading showed a significant difference with the development of the growth process, the net photosynthetic rate increased significantly with the prolonged light for accumulating more dry matter. Different photosensitive materials had different regulating mechanisms of endogenous hormones under different photoperiod treatments. The accumulation of IAA content to a certain concentration could promote the plant heading. IAA was significantly positively correlated with GA and ZR, with correlation coefficients of 0.51 and 0.40, respectively, while it was significantly negatively correlated with ABA, with the value of -0.62. The ABA content was negatively correlated with GA and ZR, with the value of -0.70 and -0.39, respectively, and the GA content was positively correlated with ZR, with the values of 0.47. The grain protein content of different light-sensitive materials under the short day in the whole growth period was significantly higher than that of other treatments. The grain protein content of N1, N2 and N3 under short day in the whole growth period were 18.89%, 80.50% and 61.23% higher than those of long day in the whole growth period, respectively, indicating that the light-sensitive material was more susceptible to short-day sunshine than the light-insensitive material.【Conclusion】The photoperiod significantly affected the growth and endogenous hormone content in different photosensitivity materials. Long day significantly prolonged the growth period, increased plant height and enhanced leaf net photosynthetic rate, but decreased the grain protein content in broomcorn millet. IAA content to a certain concentration could promote the transformation of broomcorn millet from vegetative to reproductive growth.

Key words: photoperiod, broomcorn millet, endogenous hormones, plant height, net photosynthetic rate, grain protein content