Correlation Analysis Between Pollen Fertility And Panicle Exsertion In P (T) GMS Rice With Eui Gene And The Primary Cloning Of Eui Gene

Panicle enclosure is a typical phenotype of almost all male-sterile lines, which greatly reduces seed production of hybrid rice due to its blocking of normal pollination. Elongated uppermost inter node {eui) gene can promote elongation of the uppermost internode, which is a very useful genetical factor for eliminating panicle enclosure. However, the panicle enclosure in P(T)GMS( photo or thermo-sensitive genic male sterile) rice with eui gene shows substantial variation at different heading stages. In this paper, Pei' ai 64S was used as control to analyze the relationship of P(T)GMS rice with eui gene between pollen fertility and panicle exsertion. And the different DNA character of P(T)GMS rice with eui was identified by ISSR analyse. Though eui gene was once cloned, there was some difference among different materials. In this paper specific expression cDNA sequences of the uppermost internode for P(T)GMS rice with eui gene were isolated and cloned by using suppression subtractive hybridization (SSH). The main results were as follows:(1) Under condition of natural long day-length and high temperature, P(T)GMS rice with eui gene was male-sterile and the panicle exsertion increased with increasing of total sterile pollens in per anther. The pollen became stainable and panicle exsertion increased under condition of natural short day-length and low temperature. When the percentage of stained pollen was 0.01%-—10.00%, significant correlation was found between stained pollen and panicle exsertion. As the percentage of stained pollen was higher then 10. 00%, the correlation was decreased gradually. The length of first internode had the similar correlation with the percentage of stained pollen.Similar correlation between pollen fertility and length of first internode in P(T)GMS rice with eui gene and Pei' ai 64S (PTGMS rice without eui gene) were recorded under temperature from 28℃ to 20°C. While the length of first internode in P(T)GMS rice with eui gene showed more variation than in Pei' ai 64S.(2)P(T)GMS rice with eui gene and Pei' ai 64S were amplified using 37 ISSR primers. No different band was showed among polymorphism bands.(3) A subtracted cDNA library specific to P(T)GMS rice with eui gene was constructed by SSH and pGEM-T Easy Vector cloning, which consisted of 130 individual recombinant clones. Each clone had an insert of the average size about 185 bp. Using PCR-select differential screening kit, the 96 recombinant clones of the constructed above cDNA library were chosen randomly and then hybridized with forward and reverse subtracted probes and unsubtracted probes. The results showed that 20 positive clones specific to the elongated uppermost internode of P(T)GMS rice with eui gene were obtained. To confirm their positive results, 8 clones of them were chosen randomly from the above positive clones and analyzed by Northern blot hybridization. The result proved that a probe from candidate clones specifically hybridized with P(T)GMS rice with eui gene mRNA. But to discuss whether the clone is related with elongated uppermost internode should after getting the whole length and further analyses.