Study On Reproductive Biology Of Lycium Ruthenicum

Lycium ruthenicum Murr belongs to Lycium Linn in Solanaceae,which is a drought-resistance,cold-resistant,salt-tolerance and deciduous thorny shrub,and widely distributed in Gansu,Qinghai,Ningxia,Xinjiang and other places in China.Its fruit is rich in the nutrients such as Lycium ruthenicum polysaccharides.It is a medicinal plant with high economic and nutritional value.The reproductive biology of Lycium ruthenicum was studied by a combination of field test and microscope examination in the paper.The material was collected from the agronomy practice base of He Xi University,Zhangye.The main results were listed below:1)The microsporogenesis,megasporogenesis and development of male and female gametophyte of Lycium ruthenicum were observed by paraffin section.The anthers are 4-sporangiate.The type of meiosis of microspore mother cells is simultaneous type.When the gynoecium become maturity,the ovules attached to the central axis of the ovary which has two locules,the ovules are of anatropous,simple integument and thin nucellus,and the development of embryo sac belongs to the polygonum type;2)Flowering phenology and floral morphological characteristics were observed.The Lycium ruthenicum comes into bloom from May to August.The life span of one single flower is approximately 3 days,the life span of one single strain is 64 days approximately,and the flowering span among population is 77 days.The duration of the flowering peak period is 26 days,and the final flowering stage on August 9th.The corolla of Lycium ruthenicum is funnel-shaped,the diameter about 8-12mm,and 2-4flowers in clusters.The petals colour is purple or pink.According to the process of the development,the florescence of Lycium ruthenicum could be divided into 5distinctive stages:squaring period,tiny buds period,corolla growth period,flowering period and withering period;3)Breeding system of Lycium ruthenicum was researched.Pollen grains of the genus is oval,3-lobed-subglobose and 3-colporate.The shape of the germinal furrow is slender bar.Pollen surface ornamentation is long strip.The highest pollen viability of Lycium ruthenicum was obtained in the first day of blooming,reaching 78.7%.The life span of pollen was about 2-3 days in natural conditions.The stigma of Lycium ruthenicum had receptivity in the two days before opening and higher receptivity in0-1 days.This results indicated that the optimum artificial pollination time for Lycium ruthenicum is 24 hours after blooming.The Pollen-ovule ratio is?521.06±10.84?.The Outcrossing index is 4.Based on the results of bag mark experiment,the breeding system of Lycium ruthenicum was xenogamy,some of them are self-compatible,pollination requires pollinators;4)Lycium ruthenicum is insect-pollinated.The flower visiting insects and th eir behavior were observed.Total 6 visitors was found and they belong to Dip tera and Hymenoptera respectively.Aplis mellifera Linnaeus,Eristalis tenax Lin naeus and Metasyrphus corollae were the main pollination insects.The process of pollen germination was observed in vitro.The results showed that the opti mal culture medium for germination was 120g?L^-1sucrose+10mg?L^-1H₃BO₃+10mg?L^-1CaCl₂,the germination temperature was 20?.The growth of the pollen tube is slow after 6 hours culture in dark.