Effects Of LTP And Internal And External Microorganisms On Pollen Germination Of Carya Illinoinensis

In this experiment,pecan(Carya illinoinensis)pollen was used as material.Based on the in vitro germination system of pecan pollen,the regulatory genes and microorganisms affecting in vitro germination were discussed.The Carya lipid transfer protein genes LTP1 and LTP2 were cloned,and their bioinformatics analysis and quantitative expression analysis were carried out to further verify their function in pollen germination.At the same time,the effect of microorganisms on in vitro germination of pecan pollen was studied,in order to lay a foundation for the breeding improvement and growth regulation of pecan,and provide technical support for the study of pollen germination characteristics.The main results are as follows:(1)LTP was significantly different before and after germination between pecan and Carya cathayensis.Carya LTP has the typical structural characteristics of nonspecific lipid transfer protein and has a conserved domain.However,it was found that the addition of exogenous LTP to the pollen germination system had no significant effect on the pollen germination rate and pollen tube length of pecan.(2)Three endophytic bacteria Pantoea agglomerans,Pantoea vagans and Xanthomonas campestris were isolated from pecan pollen.The addition of these three endophytic bacteria to the pollen in vitro germination system had no significant effect on pollen germination;Adding a certain concentration of streptomycin and ampicillin can significantly improve the pollen germination rate and pollen tube length,while a certain concentration of gentamicin sulfate can inhibit pollen germination.(3)After 2 days of storage at room temperature,the pollen germination ability of pecan decreased by about 19.0 %;The addition of yeast 15B1 medium had no significant effect on the in vitro germination of normal pollen,but it could significantly improve the pollen whose germination ability decreased significantly after storage at room temperature for 2 days,with an average increase of 33.6 %,so that it could reach the germination ability of normal pollen.The active substances exist in the fermentation supernatant at the later stage of strain culture and have the characteristics of high temperature resistance.