| Go543s, a new germplasm with fertility alteration of low temperature induced sterility and high temperature induced fertility, belongs to inverse temperature-sensitive genie male sterile rice with higher critical temperature of fertility alteration. Its prospects are notinferior to those of the photo-thermo-sensitive genie male sterile lineswhich are widely employed at present. The photo-thermo sensitivity offertility alteration, heredity, sensitive part of fertility, physiological and biochemical index and seed production bases for go543s were systematically studied and discussed in this dissertation. The main results are as follows.1 The photoperiodic response of go543s was weak and classified as the second photoperiodic sensitivity level while its temperature response was medium and classified as the third temperature sensitivity level.2 The tendency of fertility alteration of go543s in Changsha district in 2002 displayed as follows: sterile stage- fertile stage -fertility fluctuation stage-fertile stage-fertility fluctuation stage-fertilestage sterile stage. The fertility fluctuation was apparently affected by temperature changes. Therefore, there were some risks for the multiplication and seed production of go543s in this area.3 The photo-thermo experiment in the phytotron showed that fertility alteration of go543s was mainly controlled by temperature and was not correlated to the light length.4 The critical temperature of fertility alteration of go543s was about 29.5 and the reliable and critical temperature for practical use, i.e. critical fertility-inducing temperature, was 29.0 . The thermo-sensitivestages of temperature-induced go543s' fertility alteration were from thestamen and pistil formation stage to pollen mother cell (PMC) meioticdivision stage and the most sensitive period was at PMC formation stage.5 The sterility of go543s, belonging to recessive inheritance, was controlled by genie genes and not related to cytoplasm, according with genetic mode controlled by two pairs of independent genie major genes, and probably involved the modification of many minor genes. At the same time, the expression of sterile genes of go543s was probably related to the genetic background of the male parent.6 The research showed that the developmental young panicle, of which the tip was 3 ~ 21cm above the ground, was the real thermo-sensitive part that accepted temperature changes to induce the fertility alteration of go543s.7 The content of reduced sugar and sucrose in leaves of go543s under low temperature was found to be constantly higher than that under high temperature and its dynamic changes during go543s' abortion showed that the lack of nutrition led to the abortion of microspore because of the shortage of carbohydrates from leaves in time.8 Peroxidase(POD) activity in leaves of go543s at different periods under low temperature was found to be higher than that under high temperature and superoxide dismutase(SOD) activity under low temperature was found to be higher than that under high temperature forthe most period, which showed that the strengthening of POD activity andchange of SOD activity under low temperature was closely related to thesterility of the pollen.9 The total content of free amino acids in sterile anther of go543s induced by low temperature was obviously less than that in fertile anther induced by high temperature and the difference of Proline(Pro) content was the most remarkable under different temperature control, which showed that low total content of free amino acids, especially the severe scarcity of Pro, led to the microspore abortion of go543s.10 The fact that the scarcity or severe scarcity of Indole acetic acid(IAA), Gibberellin(GA3), Zeatin(ZT) but the accumulation of Abscisic acid(ABA) in the young panicle of go543s and the fact that the accumulation of IAA, ABA, ZT but the scarcity of GA3 under low...
|
PDF Full Text Request