少核‘年桔’的辐射育种研究

Mutation Breeding for Citrus reticulata Blanco of Few Seeds

用60Co-γ射线4、6、8 kR辐射‘年桔’秋梢芽条,嫁接成活率分别为68.4%、41.3%和16.5%,对照成活率为93.2%。通过连续2 a的果实调查分析,获得少核性状稳定、综合性状优良的突变体4个,平均单果种子含量3.3～6.6粒,极显著低于对照的17.6粒。少核‘年桔’突变体的花粉生活力在45.5%～68.8%,发芽率在11.8%～16.7%,均分别极显著低于对照的97.3%和54.1%,说明少核‘年桔’少核的主要原因是花粉败育。

Mature autumn shoots were taken from the adult’Nianju’（Citrus reticulata Blanco）trees and the leaves of the shoots were stripped.The shoots were irradiated with gamma rays from 60Co at the dosage of 0,4,6 and 8 kR.The survivor rates were 93.2%,68.4%,41.3% and 16.5% for the 0,4,6 and 8 kR treatment,respectively.The plantlets were grown in the orchard in May of 2006.Through fruit investigation for 2 years,4 few-seeded mutants of good characters were screened.The seed contents of the 4 few-seeded mutants were 3.36.6 seeds/fruit,which were remarkably less than 17.6 seeds/fruit of the control.The pollen alive rates of the 4 few-seeded mutants were 45.5%68.8%,and pollen germination rates were 11.8%16.7%,which were obviously lower than 97.3% and 54.1% of the control respectively.One of the main causes producing few-seeded fruit was higher rate of pollen abortion.