Studies On Lagerstroemia Indica Interspecies Crossing Breeding And ‘Fenjiao Rong’ Seed Radiation Breeding

Lagerstroemia indica is one kind of garden ornamental plant with unique appreciating value,with the long flowering during the summer and the color is gorgeous, was deeply loved by people. In the past twenty years, Lagerstroemia indica is becoming more and more attention in the north and south of the Yellow River. Research on Lagerstroemia indica is mainly concentrated in management culture, physiological and biochemical characteristics,pest control and genetic basis.Less in the radiation breeding and cross breeding,This is a large extent hindered in the Lagerstroemia indica normal breeding work,more conducive to the new varieties breeding. This paper is divided into two parts. In the first part,doses of 60Co-γ ray were used to radiate the Lagerstroemia indica seed. Through the effect of different doses on crape myrtle seed germination and effects on the seedling growth effects to determine the best radiation dose. The second, Conducted on the cross breeding of the Lagerstroemia indica primary research,On how to collect nectar and pollen storage mode,selection of hybrid parent and use three kinds of hybridization pollination methods has carried on the comprehensive study.Radiation breeding effects on the Lagerstroemia indica seed germination. All the radiation could affect the Lagerstroemia indica seed germination starting time, the seed germination rate decreased with the radiation dose increased. When radiation dose is 200 Gy seed germination rate is the lowest. The difference on germination potential of ck and the germination potential of each radiation dose is significant. The difference on 150 Gy and 200 Gy radiation processing of seed germination potential is not significant. High doses of radiation affected seed germination.Radiation breeding effects on the Lagerstroemia indica seedling growth. Different radiation dose on the quality of plant height,root length,fresh and dry weight of different degrees of impact.When the radiation dose is 50 Gy,seedling growth,better plant height growth,but with the increase of radiation dose,plant height was gradually reduced.Seedling growth of normal, leaf fully extended.When the radiation dose is 150-200 Gy growing seedlings in twisted, root color yellow even can’t take out,seedling leaves serious crinkled.With the increase of radiation dose energetic seed percentage gradually decline.Determine the radiation dose of radiation breeding.In the field experiment,the induced mutation rate was 172.42 Gy,The half lethal dose of radiation was 120-220 Gy.So as to provide theoretical reference for Lagerstroemia indica mutation breeding. To obtain excellent individual variation of the Lagerstroemia indica.Lay the foundation for the Lagerstroemia indica intraspecific varieties acquired.Different disinfectants and the effect of temperature on seed germination and seedling growth. Under different time to deal with different concentration,seed germination rate,pollution rate differences.When the deal with 2.0%Na Cl O ten minute, germination rate is high,low rate of pollution,seed germination in the process of sterilization processing time and negatively correlated to the rate of pollution. When the deal with five minute,seedling growth of Na Cl O is slightly higher than that of Hg Cl2,No significant difference, to explain the high treatment methods for seedling growth.Under the condition of 25℃and 30℃seed germination starting time earlier,Other temperature seed germination initial delay time.Under the condition of 30℃,Seed contamination rate is higher,he seedling growth slow,for seed germination is not suitable,Comprehensive seed germination rate,pollution rate obtained optimum crape myrtle seed germination,seedling growth potential temperature is 25℃.Determination of pollen vigor and determination of medium.With the extension of storage time,the vitality of pollen gradually reduced.Different concentrations of sucrose and boric acid significantly influence on pollen germination,different concentration of Ca Cl2 on pollen tube elongation have different functions.When sugar is 200g/L,boric acid is 100 mg/L Lagerstroemia indica varieties pollen germination rate is higher,The pollen germination rate on the same culture conditions ‘Qiaojiaren’>‘Lager Stroemia limii Merr’>‘Lagerstroemia speciosa(L.) Pers’,When Ca Cl2 is 20mg/L,Pollen tube of each type is long.Comprehensive consideration,200 g. L-1 Sucrose + 100 mg. L-1 boric acid + 20 mg ·L-1Ca Cl2 is the best culture medium proportion.Fluorescence microscopic observation of pollen fertilization process.Lagerstroemia indica pollen fertilization fluorescence microscopic observation showed no pollen germination of pollen in the 1h after pollination.After 2h pollen began to germination,longer duration with the pollination,pollen germination is increase.after 6h pollen tube bundle,to the base of style, after 6h pollen germination quantity decreased, after 24 h complete fertilization,after 48 h large number of pollen tube death. Repeated pollination pollen tube into a bunch of elongation in the hybrid combinations,no variation phenomenon.In the pross of delay pollination and conventional pollination,Pollen tube appear interwoven,swelling and distortions, ‘Qiaojiaren’ don’t accept homologous pollen,Selfing incompatibility.