外源植物激素对小果野蕉和野蕉种子萌发率及胚活力的影响

Effects of Hormones on Musa acuminate and M.balbisiana Seeds Germination Rate and Embryonic Vitality

香蕉种子萌发率低是香蕉育种工作的重要“瓶颈”之一,香蕉种子萌发机制研究较少,严重制约了香蕉亲本组配、种质创新的进程。本研究以香蕉杂交常用可育亲本(香蕉栽培种的祖先种)小果野蕉(Musa acuminata Colla,AA)、野蕉(Musa balbisiana Colla,BB)为材料,检测不同成熟度香蕉种子萌发率的差异,研究激素处理[赤霉素(GA3),2,4-二氯苯氧乙酸(2,4-D),激动素(KT),玉米素(ZT),6-苄氨基嘌呤(6-BA)]对不同成熟程度种子胚活力及萌发率的影响。结果表明:60%、80%和100%成熟度的小果野蕉种子胚活力随成熟度提高而降低,但萌发率为0,激素处理可以提高小果野蕉胚不同部位的活力,但种子萌发率没有提高。不同成熟度的野蕉胚活力为80%>100%>60%;种子萌发率为80%>100%>60%。激素能显著提高野蕉种子的萌发率,但不同激素种类、浓度的效果有较大的差异;低浓度(50 mg/L)的激素对60%成熟度的野蕉种子的萌发率和萌发速度有较好的提高;中浓度(100 mg/L)的激素对80%成熟度野蕉种子的萌发率和萌发速度有较好的提高效果;激素会降低100%成熟度野蕉种子种子萌发率和萌发速度。80%成熟度的野蕉种子经100 mg/L的ZT处理24 h为最优组合,70 d萌发率高达34.33%。GA3、ZT、6-BA均能提高野蕉种子的胚活力,但作用于胚的位点有差异。本研究通过对两种重要的野生香蕉萌发特征进行探讨,为香蕉杂交育种理论提供依据,为杂交父母本选配和后代遗传群体构建奠定基础。

The low germination rate of banana seeds is one of the "bottlenecks" in banana breeding work.And such point block the germ source innovation in cross breeding.This study focuses on two important ancestors of modern cultivars,Musa acuminate and Musa balbisiana two diploid wild bananas were used as the material to study the effects of different maturity levels on the germination rate of banana seeds,as well as the effects of hormone treatments(GA3,2,4-D,KT,ZT,6-BA) on the embryo vitality and germination rate of seeds at different maturity levels.The results showed that:the germination rate of M.acuminata seeds with 60%,80%,and 100% maturity were nearly zero,and the embryo vitality decreases with the increase of seed maturity from 60% to 100%.Different hormone treatments can affect embryo vitality but can't increase germination rate.The germination rate and embryo vitality of M.balbisiana seed were 80%>100%>60%.Hormones could significantly increase germination rate of M.balbisiana seeds,but there were significant differences among hormone types and concentrations.Low concentration hormone(50 mg/L) could improve germination rate and speed of M.balbisiana 60% maturity seeds,medium concentration hormone(100 mg/L) could significantly improve germination rate and speed of M.balbisiana 80% maturity seeds.hormone decrease germination rate and speed of M.balbisiana 100% maturity seeds.The best combination was 100 mg/L ZT treat M.balbisiana seeds with 80% maturity for 24 hours which can accelerate germination rate as higher as 34.33% after 70 days.GA3,ZT,and 6-BA increased the embryo viability of wild plantain seeds,but there were differences in the sites of action on the embryo.This study explores the germination characteristics of two important wild banana seeds,providing a basis for banana hybrid breeding theory and laying the foundation for parent selection and offspring genetic population construction of hybrid parents.