Studies On The Culture Of Immature Embryo In 'Super Red Spur' Peach

Super Red Spur, a new spur variety in peach genotype, showed great difference in growth developing and physiological characteristics compared with other peach varieties. It had short period of embryo developing, small PF value and difficult to culture. The effects of embryo culture time, hormone levels, treatment time in low temperature, salt and sugar concentration in culture medium on the immature embryo developing and the percent of normal seedling were studied in this paper with the aim to scan the best method and condition for root and bud formation in immature embryo culture. The results were as follows:(1) When peach fruits developed up to 40 days, the seeds were very small and the immature embryos were invisible. When fruits developed up to 48 days, the percent of visible immature embryos was 70%, and when up to 56 days, it was 90% and the average PF value was 0.086.(2) When the immature embryos were treated at low temperature for 80 to 90 days, the increase PF value of immature embryos, the ratio of the immature embryos turning green and the percent of normal seedlings were found better.(3) The PF value, the ratio of immature embryos turning green and the percent of normal seedling were found better on 1/3 MS medium than 1/2 MS and MS medium.(4) Sugar concentrations in the culture medium influence the immature embryo developing and the percent of normal seedlings. The PF value of embryos cultured for 48 days in the medium containing 9% sugar was found higher that those in 6% sugar, though fewer embryos were found turning green and most of the embryos became malformation. However the PF value, the number of immature embryos turning green, the percent of germination and normal seedlings were found better when the embryos cultured for 56 days in the medium containing 6% sugar compared with the medium containing 9% sugar and the seedlings grew normally.(5) 6-BA and GA3 combined at different concentrations showed little action to the immature embryos cultured 80 days in low temperature, however had some effects to the immature embryos cultured 30 days in low temperature. The medium supplemented with only 6-BA were the best when the treatment of low-temperature last for 30 days, and the percent of the normal seedlings is 16.6%.(6) The PF value and the percent of normal seedling of immature embryos with seed coats were better than the embryo without seed coats when cultured at low temperature condition.