多酚氧化酶活性与小麦抗穗发芽的关系及抗穗发芽新品种秦麦3号的选育

为更好地选育抗穗发芽小麦新品种,解决小麦生产中的穗发芽损失问题,以18个穗发芽抗性不同的小麦品种(系)为试材,以微喷人工降雨法诱导穗发芽,测定了发芽和未发芽籽粒的多酚氧化酶(PPO)活性、酚含量和吸水率,并分析了他们与穗发芽抗性之间的关系。结果表明,PPO活性、吸水率均与穗发芽率呈显著正相关,即PPO活性、吸水率越低,穗发芽抗性越强;而酚含量与穗发芽率无相关性。同时,以PPO活性为抗穗发芽能力的筛选指标,从“昌农921×东方红3号”的杂交后代中培育出了高抗穗发芽的小麦新品种秦麦3号。

The Relationship between Activity of Polyphenol Oxidase and Resistance to Pre-harvest Sprouting in Wheat and Breeding of Qinmai 3 with High Resistance to PHS

Resistance to pre-harvest sprouting(PHS) is one of the important wheat breeding objectives.In order to search new criteria of resistance to PHS and to improve selection efficiency,we investigated the activities of polyphenol oxidase(PPO) in grain and the sprouting percentages among samples of 4 wheat cultivar with high resistance or sensitivity to PHS,and compared the PPO activity,water-absorbability,phenol content and ratio of sprouting among another 11 wheat cultivars and lines.Remarkable variation of PPO activity and sprouting percentage was found in the 4 cultivars and lines.The 11 wheat cultivars and lines had different resistance to PHS,PPO activity,water-absorbability and phenol content.PPO activity and water absorbability were positively correlated with sprouting percentage significantly and very significantly,respectively,but there was no significant correlation between phenol content and sprouting percentage.In our wheat breeding program for high resistance to PHS,the selected wheat offspring with low PPO activity was determined again in moisture shanty,and the individuals with high resistance to PHS could be screened.Using this method,"Qinmai 3",registered in 2000 and high resistance to PHS,was selected and bred from the cross of "Changnong 921/ Dongfanghong 3".