Study On Flower Bud Differentiation Te Mperature And Early-flowering Mutant Of Local Strawberry Cultivars In Guangdong

Study on flower bud differentiation of strawberry in this paper with the text cultivars Huaxiang No.1 and Huaxiang No.2,breed locally and grow in Guangdong,which can grow seedlings in summer and blossom normally in autumn and winter in Guangdong(Province).To observe flower bud differentiation rules and calculate the amount of accumulated temperature of flower bud differentiation under different temperature conditions,at the same time,observing flower bud differentiation rules of Huaxiang No.2 in the breeding base and screening early-flowering trait of the second generations of mutation.The specificresults are as follows:(1)Through the observation of flower bud differentiation of the tested cultivars,process of flower bud differentiation of strawberry is divided into the following 7 stages:the undifferentiated stage,the initial stage,inflorescence differentiation stage,sepal differentiation phase,petal differentiation stage,stamen differentiation stage,pistil differentiation stageaccording to morphological changes of growing point and productionof primordia of strawberry and sequence division.(2)Strawberry flower bud differentiation process takes different time at different temperatures,the higher the temperature,the longer the time required.Huaxiang No.1 needs 33 days to complete strawberry bud differentiation at 15℃,and it takes 42 days to complete strawberry bud differentiation at 23℃.Huaxiang No.2 needs 34 days to complete flower bud differentiation at 15℃,and it takes 44 days to complete flower bud differentiation at 23℃.(3)In different temperature conditions,the amount of active accumulated temperature of strawberry flower bud differentiation is different,the higher the temperature,the greater the amount of active accumulatedtemperature.Huaxiang No.1 needs the amount of active accumulated temperature of 330℃ at 15℃ and 756℃ at 23℃.Huaxiang No.2 needs the amount of active accumulated temperature of 340℃ at 15℃ and 792℃ at 23℃.(4)The Huaxiang No.2 grown in the breeding base in the northern mountainous area of Guangdong Province were observed and the process of flower bud differentiation was recorded.In September 20 th,Huaxiang No.2 entered the initial stage of flower bud differentiation and pistil differentiation stage in October 22 nd,lasted 32 days,it takes 20 days from the pistil differentiation to the flowering stage.(5)The second generation of EMS mutation of 62 lines had the following florescence mutant lines: early-flowering nondisjunction lines,early-flowering segregation lines,early-flowering and late-flowering segregation lines and non mutant lines.Among them,there were 4 early-flowering nondisjunction lines,accounting for 6.5%,34 early-flowering segregation lines,accounting for 54.8%,17 early-flowering and late-flowering segregation lines,accounting for 27.4%.