Study On Morphological Development Of Flower Bud And Genetic Parameter Of Fruit Traits Of Precocious Walnut

This paper studied the process of floral bud development of precocious walnut and later mature walnut as well as the secdonary bud development on morphology.We also studied the development of walnut complete flower in our country.Coefficient of variability,broad-sense heritability,correlated heritability,genetic correlation coefficients,relative genetic schedule were calculated for analyzing the genetic character of walnut fruits which were gotten from precocious walnut variety Lüyuan,later mature variety Lüfeng and their 60 F1 hybrid plants.The result showed that:1.the reasearch about walnut floral bud development(1) process of female bud developmentThe process of female bud development lasted about 10 months in Taian city,which started physiological differentiation from mid-April to early May or mid-May and blossomed in mid-April or late -April in second year can be divided into 8 stages:physiological differentiation stage,morphological differentiation critical stage,appearing stage of female inflorescence primordium and pedicel primordium,appearing stage of female flower primordium,appearing stage of bract primordium,appearing stage of calyx primordium and pistil primordia,appearing stage of immature embryo, mature period of female flower.(2) process of male bud developmentThe process of male bud development can be divided into 7 stages: squama differentiation stage,male inflorescence differentiation stage, appearance of male flower primordium,appearance of male flower perianth, appearance of male flower primordium,anther differentiation stage,mature period of male flower.In taian city,the squama started differentiated in mixed bud in late March;Male inflorescence differentiated with new shoot elongation in early or mid-April;With the male inflorescence primordium developmented male flower primordium appeared on proximal of squama; Male flower perianth differentiated in early May;Stamen primordium differentiated after male flower perianth primordium appeared 5 days.Anther differentiated in late june;Male flower matured in mid-April or late April.We beieve:the squama organization formed in male inflorescence differentiation stage was similar to receptacle,on proximal of the squama the male flower primordium appeared,the front-end of the squama played the function of flower perianth.2.the syudy on genetic parameter of walnut fruit traits(1) the variation of walnut fruit traitsThere was wide variation of fruit traits in walnut hybridization colony,especially the variation coefficient of fruit number of per plant and the nut yield of per plant and the kernel yield of per plant reached above 90%.(2) the genetic parameters for fruit traits of walnutHeritability of fruits were high widely,the heritability of shell thickness, kernel weight,nut transverse diameter,percent of kernel,nut yield of per plant, endopleura colour,kernel yield of per plant,fresh fruit transverse diameter, fresh fruit slot transverse diameter,fruit number of per plant,fresh fruit weight and fresh fruit vertical diameter were between 0.716 to 0.998.Only the heritability of moist nut weight,nut weight,nut transverse diameter,and shell weight were between 0.339 to 0.478.The variation coefficient of fruit number of per plant,nut yield of per plant and kernel yield of per plant were most great,the variation coefficient of kernel weight,shell thickness and fresh fruit weight were more bigger too.(3) correlation heritabilityThe genetic correlation coefficients between walnut fruit traits are mostly significance at 1%level or at 5%level,but the correlated heritability between walnut fruit traits less than broad-sense heritability of target trait.The correlated heritability between nut yield of per plant and kernel yield of per plant was a little bigger than the heritability of kernel yield of per plant,the correlated heritability between nut yield of per plant and fruit number of per plant was a little bigger than the beritability of fruit number of per plant,the correlated heritability between kernel yield of per plant and fruit number of per plant was a little bigger than the heritability of fruit number of per plant.(4) path analysisPath analysis show that:the direct effect of fruit number of per plant,nut yield of per plant,fresh fruit vertical diameter,nut vertical diameter,nut slot transverse diameter,shell thickness,kernel weight to kernel yield of per plant are significance at 1%level or at 5%level.The direct effect of fruit number of per plant,nut yield of per plant to kernel yield of per plant were obviously greater than the other traits,the shell thickness played negative effect to kernel yield of per plant.Most traits affected the kernel yield of per plant through nut yield of per plant,then through fruit number of per plant.For kernel yield of per plant,the nut yield of per plant and fruit number of per plant is most important reasonable factor.Decision coefficient also show that the nut yield of per plant was master decision factor,however the fruit vertical diameter was master restriction factor.(5)result of selectingWe identified 1-6,5-16,4-2,5-11 were superior tree for fruit trait using selection index and direct selection.