| Male sterility is one of the important traits for the use of rice heterosis. The progeny of recessive gms line appeares separation and be difficult to maintain, its heterosis utilization inferior to cytoplasmic male sterile lines. For these reason, its research is few relatively. However, the recessive gms line has simple heredity, stable sterility and independent of the light and temperature condition. It also makes for the research with infertility mechanism and heterosis utilization; it is beneficial to break adverse chain and achieves beneficial genes stack, it can be used as the recurrent selection to breed good materials and provide for widening germplasm resources.These researches used406.8Gy60Coy irradiation to treat dried seeds and obtained a lot of rice male sterility materials. Three genic male sterile plants with thorough and stable sterility were obtained from the M3population. Comparing the morphological characteristics and the fertility expression, cytological observation and researching genetic model and allelic analysis, we concluded these:1. Observe3male sterile mutants morphological characteristics and the fertility expression indicated, all of the leaf types were compact. The leaf colour of msl became deep green, and light green for ms2and ms3. The characterics of male sterile anthers presented watery lesions, msl was ivory white, ms2and ms3were white. The CK, comparing mutants, was yellow and clearly enrich. The pollen sterility of3mutants were all more than99.74%, the natural seed set under3.26%and the bagged seed set0%. As well as the CK, its natural seed set is93.10%and the bagged seed set69.67%. Because of the CK didn’t appeare male sterile mutants, these mutants come into being by irradiation.2. Research the growth and development process and main agronomic characters showed, comparing with the CK, the growth period of3male sterile mutants were longer, msl was longest,119days,6days more than CK, ms2and ms3were separately2days and4days more than CK. The flag leaf of ms1was lengthier and wider comparing to CK, and also ms1with higher tillering ability and the highest plant height with113.83cm,11.11%more than CK with102.45cm. Flag leaf length and flag leaf width of ms2and ms3were more or less the same, and also they had higher tillering ability. The plant height of ms2and ms3were closed with95.15cm and97.17,7.1%and5.1%lower than CK separately.3.Compared on survival rate and growth and development with male sterility stubbles of rice showed that the male sterility mutants could breed by staying stubbles and the survival rate of regenerated buds were all more than65percent. By means of staying stubbles could shorten the growth period obviously with shortening the vegetative growth phase.4. Cytological observation on microsporogenesis showed that msl developed normally before mononuclear microspore stage, its abortion occurred mainly from mononuclear stage to two-cell pollen stage. The main reason was that the tapetum disintegrates prematurely and msl belonged to typical abortion.Ms2and ms3showed that the tapetum cell delayed disintegration. At microspore meiosis phase and mononuclear microspore stage, the tapetum didn’t disintegrate but become thicker until single nucleus late stage rapid disintegration and disappeared. Their spores abortion occurred mainly from dyad stage to tetrad stage belonged to non-pollen type abortion.5. Genetic analysis indicated that the F1that3male sterility mutants acrossed CK were completely fertile and nextly self-bred F2, the segregation ratio was3:1, and then with male sterility stubbles as female parent, its test acrossed of F1, the segregation ratio was1:1. It indicated that msl, ms2and ms3were controlled genetically by single recessive gene. And with male sterility stubbles as female parent taken allelism test with F1showed that there were2non-alleles mutants of ms1and ms2, ms1and ms3, and1allele gene were mutants of ms2and ms3. |
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