PLANT REGENERATION FROM IMMATURE EMBRYO IN CHINESE JUJUBE (ZIZIPHUS JUJUBA MILL.)

In order to overcome embryo abortion and efficiently use male sterile germplasm as female parent in cross breeding of Chinese jujube, embryo rescue system was explored and established using germplasm ‘male sterile No.1 (JMS1)’, ‘male sterile No.3 (JMS3)’ and ‘Daxuezao’. The results showed that plant regeneration from immature embryo was obviously influenced by genotype, embryo age and hormones.
Among them, embryo age was the key factor.
Plants were directly regenerated from embryos at late cotyledonal stage.
In contrast, plants regenerated from invisible or barely visible young embryos through two steps, i.e., cotyledonal embryo formation and plant regeneration.
A successful rescue for very young embryo took about 60 days.
Firstly, the young embryos were cultured in medium MS+ IAA 0~2.0 mg/L+ BA 0~0.5 mg/L + sugar 50 g/L+ agar 3.3 g/L +LH 800 mg/L+ activated carbon 1 g/L until it developed into cotyledonal stage about 30 days later.
Secondly, the cotyledonal embryos were transferred into medium MS+sugar 50 g/L+agar 3.3 g/L+ LH 500 mg/L+IBA 0.1 mg/L +BA 0.5 mg/L+ NAA 0.1 mg/L, and regenerated plants were obtained about 30 days after.
The rate of cotyledonal embryo formation in JMS3 and ‘Daxuezao’ reached as high as 61.0 and 75.6%. Plant regeneration rate of JMS3 was only 6.4%. In addition, cotyledonal embryo formation in JMS3 and ‘Daxuezao’ was not significantly accelerated by 10 days dark treatment.

I International Jujube Symposium

J.R. Wang, M. Zhang, M.J. Liu*

Chinese jujube, male sterile germplasm, embryo abortion, embryo rescue, young embryo, plant regeneration

https://doi.org/10.17660/ActaHortic.2009.840.35