The Endogenous Hormones Analysis And Dwarf Male-sterile Phenomenon Of Cell Nuclear Sterile Mutant Induced By Space Radiation In Maize

Maize Research Institute of Sichuan Agricultural University(MRI,SAU) sent maize seeds for satellite abroad in 1996.A male sterile mutant was found among six excellent maize materials.The research indicated that the mutant are controlled by a pair of recessive solo gene which lied in cell nucleolus,and male sterility plant often associated with reduced plant height.In order to exploring the genetic relationship and physiological mechanism of male sterile entry's sterile and dwarfing action,the experiment takes the male sterile entry as research subject and the main study content including:(1) investigating the plant height of offsprings of several population,which contains sister crossing population,test crossing population and selfcrossing population of maize cell nuclear sterility induced by space radiation,under the background of different genetic analysis of changes in height,presumably the sterile mutants reduced the genetic mechanism.(2) understanding of the male sterile and dwarfing action and gibberellin relationship of cell nucleus sterility maize material when treated by GA₃.(3) using HPLC measur the content of ABA,IAA,ZT and GA₃ of cell nucleus sterility maize material, analyzing the relationship of endogenous hormone contents and sterility.The experiment has gained primary result as follows:1.The investigation to offspring's plant height of sister crossing population and selfcrossing population of maize cell nuclear sterility indicate that the difference of plant height between fertile and sterile material are significant(p＜1%) in all population.Make the male sterile plant cross with high selfcrossing line 178 and dwarf selfcrossing line 478 respectively,analyzing the sterile plant among their F2 offsprings show that the plant height of sterile plant of F2 crossed with 178 have no significant difference with the sterile plant of F2 crossed with 478,Which means the dwarfing effect of the sterile material is stable,and they have the same effect in every different genetic background and populations which has different fertilizability.Analyzing the plant height of the homozygous male fertile plants and heterozygous male fertile plants in fertile plants of F2 population which is from the crossing of sterile material with 178 and 478 respectively prove that there is no significant difference between the plant height of the homozygous male fertile plants and heterozygous male fertile plants in fertile plants of F2 population which is from the crossing of sterile material with 178 and 478 respectively.Inferring from above results that there is no dosage compensation effect of the sterile gene to plant height.2.The subject treated by GA₃ is offspings population of sister crossing of cell nuclear sterile material.The fertility of sterile material have not impacted when using GA₃ in seedling stage and jointing stage by analyzing the fertility and plant height of control and treatment.Before GA₃ treatment, the height of fertile and sterile plant have increased dramatically and equally,are higher than the height of control significantly and equally,as time following,the difference become less in amount and there is no significant difference between the two when adult plant.In every stage of investigation,the difference of plant height between the fertile and sterile plant are always significant,which indicate that the effect to plant height of fertile and sterile plant is the same when treated by GA₃,the dwarfing phenomenon of sterile plant is not only triggered by GA₃ deficiency.3.Taking the fertile and sterile plant of offspings population by sister crossing of cell nuclear sterile material as subject,measuring the endogenous hormones content of four stages:seedling stage, jointing stage,stage before earing and stage after eating.The result is that the ZT,GA₃,IAA and ABA content have significant difference between fertile and sterile plant both in nutrition growth stage and reproduction growth stage,and the ZT,GA₃ and IAA content of fertile plant are generally higher than sterile plant,and the ABA content is just the opposite;and the maximum GA₃ content is in seedling stage,the maximum IAA,ABA and ZT content is in stage before earing.The maximum difference of four hormones content is in stage before eating in both fertile plant and sterile plant;the changing tendency of four endogenous hormones ratio between fertile plant and sterile plant is different equally.