Floral Morphological Traits, Storage Characteristic And Heat Resistance On Pollen In Wild Actinidia Eriantha Male Plants

Present study was carried out in order to investigate the variation of floral morphological traits in wild male plants from Actinidia eriantha variety. Fifty-one wild male plant germplasm resources of A. eriantha Benth in Magu Mountain area, Nancheng County, Jiangxi province were selected as experimental materials. The DUS test Standard(for genus Actinidia) was adopted to conduct field observations and laboratory analysis.Beside the significance of floral character variation in genetic diversity,reproductive organ traits also should be considered so that successful fruit set in kiwifruit depends on several reproductive processes including pollen germination and pollen tube growth. We investigated impacts of heat stress temperatures(27?,30?,33? and 36?)on pollen germination and pollen tube growth of twenty five wild A. erianthagenotypes which were randomly chosen within present 51 wild male plants. Before heat stress application, pollens were stored at-20? for six months.We also examined the influence of storage time on germinability and tube growth of freeze stored pollens. Pollens were kept in the freezer more six months to determine changing at germinability in time from six months to one year. In vitro germination was conducted in certain cultural medium defined for Actinidia genus. Afterwards we examined fertilization ability of stored pollens of 8 genotypes, which had high or low germination percentages with didn't germinated,chosen from 25 genotypes and investigated effect of stored pollens from ‘MH67', ‘MH55',‘MH48' and ‘MH45' genotypes on fruit quality of the female experimental plant ‘M3'.Non-pollinated ‘M3' kiwifruit plant was taken as control.The results were as follows:1.Cluster analysis of floral morphological traits in wild male plants from A. erianthaThe variation coefficient of pollen viability was biggest with 59.21% and variation coefficients were more than 20% for anthocyanin degree of calyx crack in the petal base,pedicel length, number of buds and petal color indexes. 51 germplasm resources divided into 3 main classes and 2 independent plants in clustering with the average Euclidean distance was 4.10 by the DPS9.50 analysis software. Class(I) displayed high pollen viability, Class(?) displayed small flowers and Class(?) displayed dark colored flower type. Large variation was found in flower morphology of wild male plants from A.eriantha namely the genetic diversity was rich. This research can provide a theoretical base for specific germplasm screening and breeding of wild male plants from A. eriantha variety.2.Effects of heat stress on germination and tube growth of stored pollen in A. erianthaLarge variation was observed among genotypes at each treatment. Eight genotypes showed no significant change in the reduction of germination percentage. Some genotypes gave unsteady response in tube growth. MH22, MH30 and MH58 were evaluated as bettertolerant genotypes. In contrast, MH48 and MH67 were the two most sensitive genotypes.Our research will be helpful for new varieties breeding using stored pollen identified as tolerant in future breeding programs.3.Influence of Storage Time on Pollen TraitsThe germination percentages and tube lengths of genotypes decreased at the end of storage period. MH22, MH45, MH47, MH56, MH67, MH70, MH71, MH72, MH74,MH55 and MH61 genotypes were evaluated as vigor genotypes, because they maintained their viability and germination capability displaying statistically insignificant decreasing although their tube lengths significantly decreased except MH67. This investigation provided to determine some robust wild male germplasm resources in A. eriantha in point of durability of pollens against long term conservation for using at future pollination and breeding programs.4.Effects of stored pollens from wild A. eriantha plants on fruit quality characters of experimental plant ‘MH3'There were significant differences in vitro germination and fertilization ability of different stored pollen sources, and also fruit quality characters including dry matter, total sugar, titreable acid, vitamin C, total polyphenol, total flavonoid, chlorophyll(‘a', ‘b', and total) and carotenoid contents except total soluble solid content among the fruits. MH67 and MH45 genotypes were evaluated as the most suitable pollinizers which could be recommended as new candidate cultivars because of getting desired characteristics and also to be investigated more at further breeding studies.