棉花芽期抗冷性鉴定方法及抗冷性机理的研究

 以芽期抗冷性品种鲁棉研16和冷敏感品种中404A为材料，确定了棉花芽期的抗冷性鉴定方法，同时对14个棉花新材料进行了芽期抗冷性筛选。结果表明：棉花芽经过5 d 4℃冷处理后常温恢复生长7 d后的子叶平展率可作为棉花芽期的抗冷性鉴定的指标；14个棉花新材料的芽期抗冷性差异达极显著水平。筛选出芽期达到抗冷水平的棉花新材料2个,分别为7开5和7开10两个材料；芽期达到耐冷水平的材料有9个；芽期不抗冷的材料有3个。棉花芽期抗冷的机理有：不定根的发生能力越强，则抗冷性越强；胚根的向地性越强，则抗冷性越强。

Studies on Identification Way and Mechanism of Chilling Resistance at Bud Bursting Period in Cotton

The chilling resistance identification of cotton at bud bursting period was studied with chilling-resistant variety Lumianyan 16 and chilling-susceptible variety Zhong 404A, treated with 4℃ low temperature. The results showed that percentage of cotyledon unfolding of bud recovering 7 days after 5 days, 4℃ chilling treatment could be as a chilling resistance identification index at the cotton bud bursting period. We have also investigated the chilling resistance of 14 different lines at bud bursting period. The results showed that the chilling resistance of different lines at bud bursting period had significant difference. Two cotton lines with strong resistance level and nine cotton lines with middle resistance level to chilling have been screened. The chilling resistance mechanisms of cotton bud have two ways: with the occurring ability of adventitious root rising after chilling treatment, the chilling resistance of cotton at bud bursting period is stronger; and the gravitropism of cotton radicula is also a key factor concerning the chilling resistance of cotton at bud bursting period.