| Rice lodging is one of the important factors that affects higher and stable yield and quality of rice.The occurrence of rice lodging severely limits the popularization of mechanized harvesting of rice.Bacterial leaf blight is one of the most serious bacterial diseases in rice production.The source of the disease is complicated and dangerous.However,chemical controlling is not effective.It is the most economical and effective way to cultivate rice varieties resistant against bacterial leaf blight.Rice blast has become a common disease in six rice regions in China.At present,there are little of the Photo-thermo-sensitive genic male sterility(PTGMS)lines resistance to rice blast.Therefore,it is very important to develop the PTGMS lines that resistance of lodging,bacterial blight,and rice blast in rice breeding program in our country.In this study,seven PTGMS lines were selected from the progeny between “Hua1015S” and lodging resistant material “XJ12200-1”,and they were tested for lodging resistance,bacterial leaf blight resistance and blast resistance,and fertility alteration.The evaluation of the main agronomic traits and combining ability provided the basis for practical application in future breeding program.The main results are as following:1?The identification for characteristics of fertility alteration showed that the critical temperature point of five PTGMS lines,Hua 5091 S,Hua 5124 S,Hua 5306 S,Hua 5310 S and Hua 5325 S was relatively lower approximately at 23? and the stable sterile period could last up to 55-80 days under natural conditions,which is in accordance with the basic requirements of rice PTGMS lines,and it was need to conduct further evaluation on other traits of interest.Among them,plant growth duration of four PTGMS lines was 1-4 days longer than Hua1015 S,but was identical to Hua 5325 S,which showed shorter plant height,strong stems,few tillers and large panicles with many spikelets.Hua5306 S with the average plant height 98.3cm,was 9.6cm higher than that of Hua1015 S,while the other 3 PTGMS lines were slightly shorter than that of Hua1015 S.The total number of spikelets per panicle of 5 new sterile lines was all more than 1015 S.However,the total stigma exposure rate was lower than that of Hua1015 S.2?The results of lodging resistance evaluation based on measurement of related indicators showed that the lodging resistance of three PTGMS lines,Hua5124 S,Hua5306S and Hua5325 S was significantly higher than that of the parental line Hua1015 S,and the highest is Hua5306 S,and Hua 5091 S and Hua5310 Sshowed identical resistance level to the control.3?The identification of bacterial blight(BB)resistance and blast resistance of five newly developed PTGMS lines showed that high resistance to different bacterial blight and blast strains,The inoculation tests of BB indicated all five PTGMS lines with high and broad-spectrum resistance.Meanwhile,the results of blast resistance identification in the blast epidemic field of En'shi and Yichang City showed that the leaf blast of Hua5091 S,Hua5124S,Hua5306 S,Hua5310S and Hua5325 S ranked at 1 to 3 level,similar to Hua1015 S.In addition to the Hua5124 S panicle blast occurrence rate that has reached 47%,which is significantly higher than the Hua1015 S,the other four lines of panicle blast incidence were 4.0%-13.0%,similar to Hua1015 S.Artificially inoculated with 35 M.grisea strains to identify leaf blast showed that the resistance frequency of Hua5306 S was 94.3%,and the resistance frequency of the other four PTGMS lines was 100%.4?The combining ability analysis of yield showed that Hua5325 S had a strongest general combining ability.Hua5325 S could be to develop new combinations with early maturity,shorter plants,higher yield,but lower amylose content.Through the heterosis identification of testing crosses,two combinations,Hua5325S/Huarun 2 and Hua5325S/Wushan simiao were screened out,wich had early maturity,high yield,and high quality rice,it was need to produce hybrid seedes and make multi-side yield test. |
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