Study On Seed Germination And Vigor Characteristics And Transcriptomic Analysis Of Rice Dual-Purpose Male Sterile Lines

In this study,15 Dual-purpose Genic Male Sterile Lines bred in Yunnan were used as materials to analyze the differences of seed germination rate and seed vigor of the tested male sterile lines,as well as the differences of seed germination rate and seed vigor after treatment of artificial accelerated aging,low temperature and flooding.The transcriptome analysis of the two male sterile lines Chang D26 S and 1146 S,with significant difference in seed storage resistance,was carried out in order to screen the Dual-purpose Genic Male Sterile Lines of rice with high seed vigor,strong stress resistance and storage resistance,and to explore the mechanism of seed storage resistance,so as to provide theoretical guidance for the breeding of high seed vigor rice varieties.The main results are as follows:(1)The percentage of fresh non-germinating seeds of 15 male sterile lines was low,indicating that their seed dormancy was not strong.Except C815 S,the seed germination rates of the other 14 male sterile lines were more than 90%,indicating that the seeds of these14 male sterile lines had good germination characteristics.(2)With the extension of artificial accelerated aging treatment time,the seed germination rate and seed vigor index of the tested materials decreased significantly.The seeds of male sterile lines 1146 S and N111 S had the best storage tolerance,while the storage resistance of the Chang D26 S,Zhuo 234 S,Yun 9S and Z2326 S seeds was poor.(3)With the decrease of temperature,the seed germination rate and seed vigor of the tested materials decreased,and the seeds of male sterile lines 388 S,Zhuo 234 S and Chang D26 S had strong low temperature tolerance.(4)With the increase of flooding depth,the seed germination rate and bud length of the tested materials decreased,and the number of lateral roots increased.The male sterile lines388 S,Z2326S and Yun 9S had strong submergence tolerance,while 800 S and Wang S had poor submergence tolerance.(5)Transcriptomic analysis showed that after 7 days of artificial accelerated aging treatment,the number of differentially expressed genes of male sterile line 1146 S with strong storage tolerance was significantly higher than that of male sterile line Chang D26 S with weak storage tolerance,which were 2355 differentially expressed genes and 1194 differentially expressed genes,respectively.KEGG analysis showed that 1146 S seeds,after aging treatment,were mainly enriched in ribosome,oxidative phosphorylation pathway,spliceosome and ubiquitin-mediated proteolysis pathway.After aging treatment,Chang D26 S seeds were mainly enriched in oxidative phosphorylation,ribosome,spliceosome and endoplasmic reticulum protein processing,indicating that artificial accelerated aging treatment mainly affected oxidative phosphorylation,ribosome and protein synthesis and processing.(6)After 7 days of aging treatment,the expression of genes related to translation process and oxidative phosphorylation process in 1146 S and Chang D26 S were compared.The results showed that 7 translation-related genes were down-regulated and 34 genes were up-regulated.The difference multiples of these genes in 1146 S were higher than that in Chang D26 S.A total of 23 genes related to oxidative phosphorylation were identified.Among the up-regulated genes,the fold-change of 1146 S was higher than that of Chang D26S(except Os03g0278900 and Os04g0343050).And among the down-regulated genes,the fold-change of Os07g0645400,Os12g0191150,Os07g0549700 and Os01g0866500 in Chang D26 S were higher than that of 1146 S,which may lead to the difference in storage tolerance between 1146 S and Chang D26 S.