糜子矮秆突变体778农艺性状调查及其对GA的敏感性分析

为探讨糜子矮秆突变体与原始材料农艺性状存在的差异及其矮化原因是否与赤霉素(GA)合成或信号传递途径有关,以糜子矮秆突变体778和其原始材料高秆260为材料,在苗期进行形态学观察,在成熟期对株高、穗长、节间长、节间数、种子长、种子宽和穗粒数等7个田间农艺性状进行测定,同时在不同生长时期使用不同浓度GA处理植株,对处理后的株高、根长、GA敏感系数(GRI)的变化进行测量。结果显示:矮秆突变体778在苗期株高已经和原始材料高秆260产生较大的差异,这种差异主要由地上基部、第一、第二伸长节节间长度不同造成的。比较分析矮秆突变体778和原始材料高秆260的成熟期性状差异,发现矮秆突变体778的株高、穗长、节间数、穗粒数、节间长度极显著低于高秆260(P<0.01),矮秆突变体778的种子长显著高于高秆260(P<0.05)。不同浓度GA(0、50、100、200 mg·L^-1)对糜子矮秆突变体778的株高和根长无显著影响(P>0.05)。不同浓度GA对糜子高秆260的株高、根长、敏感系数GRI值有显著影响(P<0.05),高秆260在不同浓度GA处理下的植株形态及生长势与其对照组相比均有差异。在100、200 mg·L^-1的GA浓度条件下,随着时间的增加,糜子矮秆突变体778与高秆260的株高差异不断缩小至没有差异,且敏感系数GRI值在不同浓度赤霉素组之间无差异,说明外施赤霉素可以使糜子矮秆突变体778恢复到原始材料高秆260,导致突变的基因可能是赤霉素合成途径基因。

Investigation on agronomic characters of dwarf mutant in Panicum miliaceuml and analysis of its sensitivity to GA

In order to investigate the difference between agronomic traits of dwarf mutant and original material of Panicum miliaceuml and whether the cause of dwarf was related to gibberellin (GA) synthesis or signaling pathway, the dwarf mutant 778 and its original material high straw 260 were used as experimental materials. Morphological observation and determination of agronomic traits in plant height, ear length, internode length, internode number, seed length, seed width and number of seeds were determined. Then, the plants were treated by different concentrations of GA in different growth periods, and the changes of plant height, root length, stem width, leaf length and leaf width were measured. The results showed that the plant height of the dwarf mutant material was significantly different from that of the original high straw material, which was mainly caused by the difference between the base of the ground and the length of the first and second elongation joints. Comparing and analyzing the differences of traits between dwarf mutant material 778 and original high straw material 260, it was found that the plant height, ear length, internode number, grain number per ear and internode length of dwarf mutant 778 were significantly lower than that of high straw 260 (P<0.01), the seed length of dwarf mutant 778 was significantly higher than that of high straw 260 (P<0.05). Different concentrations of gibberellin (0, 50, 100, 200 mg·L^-1) had no significant effect on plant height and root length of scorpion dwarf mutant 778 (P>0.05), but different concentrations of gibberellin had significant effects on plant height, root length and GRI value of high straw 260 (P<0.05). And the plant morphology and growth potential of high straw 260 treated with different concentrations of gibberellin were superior to the control group. Under the condition of 100 and 200 mg·L^-1 GA, the difference in plant height between the dwarf mutant and the high straw material decreased with time, and there was no difference at the end. There was no difference in GRI value between different concentrations of gibberellin treatments, indicating that the external gibberellin could restore the scorpion dwarf mutant to the original high straw, and the gene that caused the mutation may be related with the gibberellin synthesis pathway.