Studies On Endosperm Culture And Ploidy Variations Of Kiwifruit

In this study, take the seed endosperm of'Hort 16A'(Actinidia chinensis cv. 'Hort 16A') as the explants, series conditions which can affect the kiwifruit endosperm culture were studied. Endosperm of kiwifruit'Hayward'(Actinidia deliciosa cv.'Hayward') and'Hort 16A'(Actinidia chinensis cv.'Hort 16A') was used as explants to study effects of plant growth regulators, dark treatment, subculture time and colchicines on the ploidy variation during endosperm culture.1 Take the seed endosperm of'Hort 16A' as the explants, Inoculate them into the half-strength MS medium with pH value of 5.8, which consists of 20g/L saccharose and 5g/L agaragar, cultivate them in the training room of 25℃,16/8h light cycle. With the combination of NAA (0,1,2 mg/L),2,4-D (0,0.5,1.0 mg/L) and BA (0.5,1,3 mg/L), we examine the effects of different combinations of plant growth regulators on endosperm callus tissue formation. The results showed that the effect of 2,4-D is more significant than that of NAA, the maximum callus induction frequency were observed in the combination of Img/L 2,4-D+lmg/L 6-BA. With the combination of NAA (0,0.1,0.5μmol/L) and BA (0,1,5,10μmol/L), we examine the effects of different types and concentration of plant growth regulators on the organogenesis of endosperm callus tissue. The results showed that the maximum induction frequency of the adventitious buds were observed in the combination of 0.1μmol/L NAA+5μmol/L BA; while the maximum induction frequency of the adventitious roots were observed in the combination of 0.5μmol/L NAA+1μmol/L BA.2 Endosperm of kiwifruit'Hayward'and'Hort 16A' was used as explants to study effects of plant growth regulators, dark treatment and subculture time on the ploidy variation during endosperm culture. The results showed that there were more 3C enneaploid callus on medium supplemented with 0.2μmol/L NAA and 5μmol/L 6-BA, higher concentration of 6-BA can increase the rate of ploidy variation in endosperm-derived callus cells; Callus had not been treated by dark treatment had fewer 3C cells and richer ploidy variations than those treated by dark for 7 day; The rate of ploidy variations in endosperm-derived callus from the same sources increased with subculture time, while the ploidy variation richness of regenerated plantlets were declined.3 Endosperm of'Hayward', and 'Hort 16A' were used to study the influence of treatment time and concentration of colchicines on the chromosome ploidy during the process of endosperm culture.The results showed that:chromosome doubling rate of endosperm callus cells of'Hayward'and'Hort 16A' gradually improved when concentration and treatment time of colchicines increased; more triploid endosperm cell were gotten when'Hayward'and'Hort 16A' endosperm was treated with 0.05% colchicines for 48h. Polyploidy regenerated plants induce best when'Hayward' endosperm callus were treated with 0.1% colchicines for 24 hour.