Studies On Immature Embryo Culture Of Hybrids Between Pistacia Vera And Pistacia Chinensis

Pistacia vera L. is economic tree of Pistacia which belonged to Anacardiaceae, the fruit called "happy fruit" is one of the world famous four dried nuts, and has great economic value. A fine variety may be cultivated by hybrid breeding between Pistacia vera and Pistacia chinensis, it is difficult to obtain hybrid seeds because the hybrid embryo abortion was serious. Immature Embryo culture is an effective way to solve the hybrid embryo abortion. Pistachio tissue culture studies had been reported at home and abroad, but the hybrid immature embryo has not been reported in recent years. In this experiment, hybrid immature embryos and mature embryos were used to study the hybrid embryo culture and rescue which including the best time to get the immature embryo, the best suitable methods of sterilization and pretreatment, the best way in which how to inducing the immature embryo, suitable proliferation and rooting medium for immature embryo seedlings. A technology system of hybrid immature embryo rescue was successfully established and laid the foundation for acquisition of hybrid seeds.The main results were summarized as follows:1. Proved the fruit growth and development of pistachio. The growth development keeps consistent between open pollination fruit and hybrid fruit, the fruit growth has a single "S" curve pattern in terms of the changing of fruit length and diameter during fruit development, growth peak from 20 to 40 days after pollination and fruit morphological development has been basically completed at 50 days; The fruit has a double "S" curve in terms of the changing of fresh weight, the first peak was from the 10 to 50 days and kept consistent with fruit morphological development period; the second peak was from the 80 to 130 days and was a critical period of the fruit kernel development and the formation.2. Identified the critical period of hybrid embryo abortion. The development of hybrid embryo began from 80 days after pollination, and the critical period for the hybrid embryo abortion was from the 80 to 100 days, this period is the best time of hybrid embryo rescue.3. The embryo age is a key factor affecting the hybrid embryo rescue. Pistachio hybrid embryo rescue appropriate age was from the 100 to 120 days, the hybrid immature embryos did not germinated at 80 days while germination rate was 37.04% and 83.33% respectively at 100 days and 120 days.4. The cold treatment is an effective method for accelerating immature hybrid embryo germination. The germination rate of immature embryos, which were kept at 5℃for 90 days and then inoculated in medium DKW, was as high as 86.67% at 20 days. 5. Seed coat is one of the important factors to affect embryo culture. When removing the seed coat can conducive to embryo germination and growth inoculating in the DKW medium with maltose as carbon source.6. The suitable multiplication medium for immature embryo seedlings was DKW + 2.0 mg·L-1 6-BA+0.05 mg·L-1 IBA+0.3 g·L-1 LH+1.5 g·L-1 PVP, with which the multiplication coefficient of 3.47 and the seedling height of 3.32 cm were obtained. 7. The suitable rooting medium was 1/2WPM+2.0 mg·L-1 IBA+0.05 mg·L-1 NAA with a rooting rate of 80%.