| The stone fruit such as peach,pulm and apricot are abundance in germplasm resources in our country. Remarkable achievement has been achieved in early-ripen cultivars and new germplasm can be created by using different cultivars or cultivars and wildness in distant hybridization as parents between peach and apricot and plum. But embryo abortion occurred often in early-ripen cultivars and distant hybridization, and also peach and apricot have difficulty in regeneration that restrict further breeding program and new germplam and related studies in fruit. The problem of embryo abortion at early stage of early-ripen cultivars and distant hybridization would be resolved by studying and establishing ovule culture procedure and efficient regeneration system of peach and apricot, and also offered a guarantee of rapid multiplication and genetic transformation and related studies for stone fruit. Aimed at the problems said as above, effects of ovule culture and immature cotyledons in stone fruits were studied and then culture procedure of ovules from hybrids' and breed nature were conducted. The whole culture procedure and regeneration system that adventitious buds induced from immature cotyledons and culture system of multiplication and rooting were established. Health and normal seedling from adventitious buds were received. The main results were as followings:(1) The ovules of Katy gathered 25days after full bloom (DAFB) were too young to find visible embryos(PF=0).The results proved that SH culture medium was better than MT culture medium for ovule culture of apricot. Capsules cut is in favor of ovules' and embryos' growth. As for inducement regeneration of adventitious buds and visible embryo, BA combined with NAA displayed stronger inducement ability than with IBA. Inducement treatment together with growth culture was performed to obtain visible embryos, and embryo producing rate up to 80％.Immature cotyledons of Katy from ovules gathered 25 and 35days after full bloom require 1.25mg/L TDZ that rate of adventitious buds is 85.00％and 80.00％, the adventitious buds filled up proximal region of cotyledons. Whereas, immature cotyledons from ovules sampled 50 and 55days after full bloom require 2.50mg/L TDZ that rate of adventitious buds were 65.00％and 60.00％and sampled 60 days after full bloom require 5.0mg/L TDZ adventitious buds rate was 61.11％and adventitious buds were mainly regenerated in areas including proximal regions, hypocotyl joints and both sides of the proximal regions, etc.In terms of favorable conditions for regeneration of adventitious buds of Katy, condition of 25℃and 21 days for dark culture for immature cotyledons from ovules sampled 35d,50d,55d,60d after full bloom, adventitious buds rate were 72.22％, 65.00％, 60.00％and55.56％. Whereas, under condition of 4℃and 28 days for dark culture, regeneration rate of adventitious buds were 59.09％, 71.42％, 77.78％and 86.36％.(2)For ovules of peach, rate of embryo of different cultivars of peach showed Early red 2 was higher than Qiannianhong and Shuguang at three stages of 28d,40d and 48d after full bloom, the results showed that the rate of embryo were 42.86％of Early red 2 gathered 28d after full bloom.Immature cotyledons of Early red 2 from ovules gathered 48d after full bloom with 0.5mg/LTDZ concentration got rate of adventitious buds as 69.69％, buds rate from immature cotyledons of Qiannianhong, Early red 2 and Zaotupantao from ovules gathered 48d after full bloom were 62.50％, 50.00％and 56.00％with 1.0mg/LTDZ concentration.(3) As above studies, four class culture system for embryo rescue of Katy and different peach were established as following, First:ovule culture were carried out to abtain visible embryo(first class);Second:growth culture of immature embryo were conducted to get faty immature embryo (second class);Third:regeneration of immature cotyledons were conducted and gain adventitious(third class); Fourth:rapid multiplication of seedlings were carried out that from adventitious buds (fourth class).
|
PDF Full Text Request