| A.sibirica is the main apricot in the north.Its almonds are rich in various nutrients,with high nutritional and economic value.It is an economic forest tree with great development potential in the Three North Region of China.The adaptability and ecological maintenance functions are also important tree species for wind and sand fixation in the north.However,In order to the change of early spring,It is the A.sibirica flowering period,and the apricot flower freeze damage often occurs,resulting in a decrease in yield.Therefore,In order to explore the response of A.sibirica early-Flowering and late-Flowering to cold.This paper takes A.sibirica with different flowering time at Inner Mongolia Autonomous Region Forest Breeding Center.Observing the flowering period for two consecutive years and analyzing the differentiation characteristics of pistils at different developmental stages,combined with the determination of physiological indicators in different developmental stages,In order to find the species that can avoid the spring night frost,provide a research basis for the extensive use of A.sibirica germplasm resources and breeding of new varieties.The research results are as follows:(1)Based on the observation of flowering period for two consecutive years,the flowering period of A.sibirica can be divided into 6 development stages,which are dormancy stage,flower bud expansion stage,red stage,flower bud stage,full flower stage and recession stage.And flowering time of different years,It is related to the temperature of the year.In the two years,the early developmental stages of early-flowering are about three to seven days earlier than the late-flowering.It takes thirty days for the early-flowering to grow from flower bud to full bloom,and the late-flowering takes about twenty four days.(2)By observing the morphological characteristics of pistil,it is found that the difference between early-flowering and late-flowering is small,and the pistil primordium has appeared in mid-October.The flower buds enter dormancy in November,and continue to the dormant end of the leap year.The flower buds enter the expansion stage,the pistil the base is obviously elongated,and the base of the pistil expands to form the ovary at the flower bud stage.When the full bloom period,the ovule is produced in the ovary,the development of the ovary is over,and the female organ is fully developed.(3)By measuring the antioxidant enzyme system in six different developmental stages of early-flowering and late-flowering at natural temperature,the results showed that the change trend of SOD enzyme activity of early-flowering and late-flowering was "M".The POD activity of early-flowering and late-flowering showed a decreasing trend.The content of MDA showed an inverted "M" type in early-flowering and late-flowering,The change of soluble sugar content in early-flowering and late-flowering was different from the dormant stage to the declining stage of A.sibirica flower.The soluble sugar content of early-flowering showed a trend of "decline-rise-fall",and the content of soluble sugar in late-flowering showed "M" type,that is,"rise-fall-rise-fall".Soluble protein also showed different performances in early-flowering and late-flowering.Early-flowering showed a trend of "decline-rise-fall",and late-flowering showed "decline-rise-fall-rise-fall",which was about "M".(4)Preliminary evaluation of the cold resistance of of A.sibirica early-flowering and late-flowering was carried out by fuzzy membership function and principal component analysis.The results showed that under natural temperature,the late-flowering was stronger than that of early-flowering under natural temperature. |
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