Studies On Characters Of Glume-gaping Grains Of Cytoplasmic Male Sterile Lines And B-lines

The experiment with 4 cytoplasmic male sterile(CMS) lines and b-lines, whichdiffered in characters of glume-gaping grains(CGG) was carried out under threeseeding dates to systematically study the distribution of glume-gaping grain on thepanicles of CMS lines, the effect of internal inherited factors and externalenvironmental factors, morphology anatomy characteristics and physiological andbiochemical characters. The main results are as follows:1 Glume-gaping grains coincided with the order of spikelets opening, percentagesof glume-gaping grains (PGG) of superior spikelets were lower than that of inferiorspikelets; the PGG of the primary branches were lower than that of the secondbranches, the PGG of the sixth grains in the primary branch was the lowest and thesecond grain was the highest in the primary branch; the distribution of FuyiA'sglume-gaping seeds were different from other CMS lines.2 With the increase of seed setting rate, the PGG of CMS lines decreasedregardless of the total number of spikelet per panicle.3 The CGG of b-line was lighter than that of the CMS line,T98A,FenyuanA werelighter than that of FuyiA,SanxianA among CMS lines. The correlation weresignificant between the PGG of the CMS line and corresponding b-line. The geneticfactor had impact on the seed with dehiscing glume.4 The external environmental factor had impact on the seed with dehiscing glumeof CMS line. In certain range the PGG of CMS line reduced, with the decrease of totalprecipitation and relative humidity and with the increase of sunshine hours duringpollinating stage. The CMS lines, which had similar CGG, had same response toweather factor, but differed in the different CGG of CMS line. The relationship wasdifferent between different CMS line with CGG and using of gibberellin. The CMSline with light CGG using gibberellin had lower PGG than those of no using gibberellin, while the CMS line with heavy CGG which had not used gibberellin hadlower PGG than those of proper using gibberellin.5 The CMS line with light CGG had wider main stem, more small vascularbundles (SVB) in main stem, lower ratio of phloem to vascular bundle in centric SVBof pedicel, small area of phloem in a circumambient SVB of pedicel, smaller area ofall circumambient SVB in pedicel, more developed conduction system in lodicule,smaller area of a SVB and larger area of all SVB in lodicule in comparison with theCMS line with heavy CGG. The PGG were high in reverse. The b-lines had similarrule. Short of vascular bundle, undeveloped and unequal tracheae in the lodicules andundeveloped conduction tissue which was one of the reason why the CGG of CMSline and b-lines were differnt. Similarly, short of tracheae in SVB, small area andundeveloped and unequal tracheae, which were one important reason why differentCMS line had different CGG.6 The CMS line with light CGG had characters of smaller angle of glume opening,smaller bulk of lodicule, lighter weight of lodicule in comparison with the CMS linewith heavy CGG. The b-lines had similar rule.7 The CMS line with light CGG had characters of lower electrical conductivity oflodicule, lower water potential of lodicule, lower peroxidase activity, higher amylaseactivity of spikelet in comparison with the CMS line with heavy CGG. The b-lineshad the similar rule.