高温对甘蓝型油菜隐性上位互作核不育稳定性的影响

Effect of high temperature on stability of recessive epistatic genic male sterile lines in Brassica napus L.

为深入了解生产中出现的微粉现象,研究了人工高温和分期播种情况下甘蓝型油菜隐性上位互作核不育纯合型不育系9012A和杂合型不育系12-204A的不育稳定性。结果表明,两种类型不育系在一定高温胁迫下,均出现育性转换现象,但对高温的敏感性有明显差异。对于9012A系,育性转换临界温度介于30-35℃之间;40℃持续处理16-32h,或者间歇处理3h/d×6d、6h/d×5d、9h/d×4d、12h/d×3d、15h/d×2^-4d（累计40℃处理18-60h）,或35℃间歇处理15h/d×2^-4d（即35℃累计30-60h）均发生育性转换,其中35℃时15h/d×3d（即35℃累计45h）处理育性转换最为明显,说明高温对9012A育性转换具有累加效应。自然条件下6个播期（从2014年10月16日到2015年2月9日,即秋冬播种,避开30℃以上持续高温）的不育性彻底稳定。对于12-204A系,育性转换临界温度为29℃,不低于29℃时育性发生转换,其中35℃15h连续处理育性转换效果最为明显;自然条件下6个播期均发生育性转换。当高温胁迫下育性发生转换时,9012A和12-204A均可自交结实,但是结实性差。

To better understand the stability of recessive epistatic genic male sterile lines in Brassica napus L.,effects of heat and sowing dates were investigated on sterile stability of 9012A（ homozygous genotype） and 12-204A（ heterozygous genotype） of B. napus. Results showed that fertility reversion was observed under certain high temperature stress,and the heat sensitivity was obviously different between the 2 lines. For 9012 A,the critical temperature of fertility reversion was between 30 and 35℃. Fertility reversion occurred under continuous treatments of 16- 32 h,or intermittent treatments of 3h / d × 6d,6h / d × 5d,9h / d × 4d,12 h / d × 3d and 15 h / d × 2- 4d at40℃（ 40℃ duration added up to 18- 60h）,or intermittent treatments of 15 h / d × 2- 4d at 35℃（ 35℃ duration added up to 30- 60h）. Among the intermittent treatments,condition of 15 h per day at 35℃ with consecutive 3 d caused the most obvious reversion. Under natural weather condition,9012 A was completely stable at 6 sowing dates（ from Oct 16,2014 to Feb 9,2015,which avoided 30℃ hight temperature during flowering）. For 12- 204 A,the critical temperature of fertility reversion was 29℃. Continuous treatment of 15 h at 35℃ led to the most obvious fertility reversion. Under natural weather condition,12- 204 A fertility obvious reversed at all 6 sowing dates above.Weak selfing seedset of both 9012 A and 12- 204 A were achieved under heat treatment,but with low yield.