抗枯萎病宝岛蕉早花突变体的筛选与鉴定OA北大核心CSTPCD

[Objective]The purpose of the study was to screen and identify Baodao banana early flowering mutant with resistance to wilt disease,to provide a reference basis for further breeding of new banana varieties with wider adapta-bility using mutant strains.[Method]By using multi-generation tissue culture breeding combined with field planting com-parative experiments,based on the screening objectives of short growth period,strong disease resistance,short plant height,high plant yield and genetic stability,excellent strains were selected from the early flowering mutant off-spring of Baodao banana.Baodao banana was used as a control,and the morphological and biological characteristics of the excel-lent mutant strains were observed and identified according to the specification for description of banana germplasm re-sources.The carbon and nitrogen nutrient accumulation at the growth point of plant corms,as well as the differences in the content of flowering related hormones indole-3-acetic acid(IAA),zein(ZR),gibberellin(GA)and abscisic acid(ABA)were measured and analyzed.Genetic differences and genetic relationship between mutants and their wild types were detected using ISSR molecular markers.Using Baodao banana and the main cultivated varieties(Guijiao No.6 and Brazilian banana)as controls,the disease resistance during the seedling stage was identified using the root injury soaking method.Regional planting experiments and field disease resistance identification were conducted in Guangxi and Hainan.[Result]An excellent mutant strain 0523 was selected(referred as 0523),with an average plant height in newly planted banana of 280.0 cm,a false stem base circumference of 80.5 cm,and a middle circumference of 60.0 cm,which were 14.0%,5.8%,and 11.8%smaller than those of Baodao banana respectively.The total number of newly harvested leaves was 26-29.There was no significant difference in fruit nutritional quality and individual plant yield compared to Baodao banana(P>0.05,the same below).The carbon nitrogen ratio at the growth point of 0523 corm was significantly higher than that of Baodao banana by 19.0%(P<0.05,the same below),while the GA and IAA contents were significantly lower by 24.8%and 22.6%respectively.The ABA and ZR contents were slightly increased compared to Baodao banana,but there was no significant difference.The identification result of disease resistance in the seedling stage showed that 0523 was moderately resistant and slightly stronger.The resistance level was slightly higher than that of Baodao banana,and Guijiao No.6 was highly susceptible.The polymorphism rate between mutant strain 0523 and Baodao banana was 8.8%,with a genetic similarity coefficient of 0.95,indicating a difference between the two.The average incidence rate of wilt disease of the newly planted banana and ratoon plant banana of 0523 in Guangxi and Hainan was 4.5%,and the aver-age incidence rate of the ratoon bananas was 3.5%,which were 87.8%and 94.1%lower than that of the main cultivated varieties,the incidence in each experimental sites were significantly lower than the main cultivated varieties.The growth period of the newly planted banana and ratoon plant banana of 0523 was significantly shortened compared to Baodao ba-nana,but had no significant difference compared to the main cultivated varieties.[Conclusion]The mutant strain 0523 has excellent traits such as resistance to wilt disease,early maturity,short plant height,and wide adaptability,which can be used to cultivate new banana varieties for large-scale promotion or further be utilized as a parent breeding material in ba-nana breeding research.