Preliminary Investigation On Breeding Of Lagerstroemia Indica Pink Velour Hybridizing

This paper takes the crape myrtle varieties of L.indica ’Jinwei’ and L.indica’Caixiamantian’ as the experimental materials to carry out the research on the measurement method for the fresh pollen viability of crape myrtle long-short stamens,and dynamic changes of pollen viability at different storage temperatures.The cross-compatibility,sterile germination of hybrid embryos in vitro,and preliminary screening of hybrid trait,etc.,are also studied taken the L.indica ’Whit Ⅲ’ as the maternal plant,and L.indica ’Jinwei’,L.indica ’Zijin’and L.indicaL’FenHudie’as the staminate plant.The main results are as follows:1.Pollen viability study showed that certain concentration of sucrose and H₃BO₃ acid and CaCl₂ could promote pollen germination.In 250g/L sucrose+20mg/L H₃BO₃+20mg/LCaCl₂ acid solution,the pollen germination rate of’Jinwei’ long stamens up to 88.33%,and the pollen germination rate of short stamen was 61.53%;the pollen germination rate of ’Caixia Mantian’ long stamen was 81.18%,and the pollen germination rate of short stamen was 50.98%.Neither staining method is suitable for the determination of pollen vigor of two crape myrtle varieties;The low temperature contributes to the storage of pollen.The pollen of two varieties can be stored for 36 days at-20℃.The pollen vigor of ’Jinwei’ long stamens was longer,which could be maintained for 40 days.The pollen vigor under storage conditions of 4℃ could be maintained for 28 days,and the pollen vigor retention time under normal temperature storage conditions was the shortest,only about 4d.2.’Whit Ⅲ’ was used as the female parent and three different colors of Chinese crape myrtle was the male parent.The results all showed higher affinity,the hybrid combination’Whit Ⅲ’ × ’Zijin’ had the highest affinity,the best fruit development,the green color of the fruit at the immature stage,the smooth surface and no cracking,and the seed setting rate was as high as 91.5%.Then,the seed setting rate of ’Whit Ⅲ’ × ’Zijin’ was 77%,however,the fruit development was poor,and there was a phenomenon of abortion or fertilization.The lowest hybrid affinity was ’Whit Ⅲ’× ’FenHudie’ was 46.5%.1/2MS medium was more suitable for the germination and growth of the hybrid immature embryos of crape myrtle.The leaves of the seedlings are large and green,followed by MS.It was concluded that the best medium for in vitro germination culture of hybrid immature seeds was as follows:the highest germination rate 66%of 1/2MS+6-BA2.0 mg/L+IBAO.lmg/L.Three different plant growth regulators have different effects on the proliferation of crape myrtle seedlings.NAA has the greatest effect on the proliferation growth of hybrid seedlings,followed by IBA.The best medium is 1/2MS+6-BA2.0 mg/L+IBA0.2mg/+NAA0mg/L,and the highest proliferation multiple is 3.76 times in culture for 60 days.3.The hybrid offspring of the combination of ’Whit Ⅲ’ and Chinese crape myrtle TenHudie’ with pink color has an advantage in growth potential,besides there were some variation in the leaf shape.Therefor it can be further studied as a material in leaf shape.The hybrid offspring of the combination ’Whit III" and Chinese crape myrtle ’Zijin’ with purple color gets the widest range of leaf color.Red leaf,yellow leaf and green leaf can appear in the combination at the same time,there were some variation in the combination,so it had advantage in breeding direction.