Research On The Potential Of Different Growth Period Of Maize

Parents used in this trial were3choice of several inbred lines of the system and10common inbred lines，both of them are come from early maturity，middle andlate variety varieties.The different growth period parents are used of NCⅡ，incomplete diallel cross estimated of GCA,SCA and reference heterosis werecalculated based on the means of combinations. Among them，42combinations wasproduced with6×7incomplete diallel cross. Field trial set up3densities,60000plant ha，75000plant ha and90000plant ha，Through field investigation and seed inspection indoor collected the data，The resultsare as follows:(1) Analysis of the heterosis Heterosis average yield per plant, Customizesystem JZ101heterosis mean value is highest, is107.36%,8-F the heterosis ofaverage is106.86%, J1207heterosis mean value of98.02%. Under the samecombination in three different density of heterosis are larger differences, but for thehybrid F1belong to premature or early in the parents, parents in the6plant ha and7.5plant ha2heterosis mean value difference is not large, but the overall trend yieldheterosis and decreased as density increases. Precocious class small variations in thehybrids of inbred lines by equipping, and have individual combination also increaseswith the increase of density increase; Medium material by equipping advantage ofaverage value change is bigger, a hybrid variety for the groups change range ofmaterials is the largest.(2) Analysis of the combining ability Integrated3groups of density measurementdata show that the combining ability of optional system J1207yield GCA effect valueunder three kinds of density are characterized by the highest (7.5plant ha) issued tothe peak, the other two optional system (JZ101,8-F) although yield GCA well underthree density, but the other properties of GCA superior to other parents, such as lengthof bald tip and grain. For yield SCA effects show that for different types of parentmedium x late mature variety or portfolio performance under low density is obvious;Medium variety x medium or medium x outstanding combination under mediumdensity; Precocious x precocious medium or premature combination under the highdensity, but the early maturity variety x combinations under three kinds of density aredifficult to piece together a high yield of hybrid combinations. (3) Analysis of the genetic parameter Test of11agronomic characters of thegenetic parameters is analyzed, showed that plant height, ear position, the malebranch, ear rows and grain length the five traits for early generation selection; Spikelength, spike, grain number and grain weight and grain weight the five traits forselection of the late generation. Bald tip long due to test error, cannot determine itschoice from generation to generation.(4) Analysis of the growth period Based on three kinds of density of sizeanalysis results show that the direct effect of the growth period under the6plant hasize as leaf number﹥ASI﹥section number﹥stem diameter; Under the7.5plant hadirect effect size for the plant height﹥leaf number﹥ASI﹥anthesis﹥stem diameter;In the direct effect of the growth period under the9plant ha size for the sectionnumber﹥leaf number﹥ASI﹥spin silk period.(5) Forecast the growth period The parents for hybridization combinationgrowth period between10days or more, the growth period of F1to precocious parent;For parents growth period were similar (5days or less), the growth period of F1tendency of value; But for the early and late maturity of inbred lines by equippinghybrid because parents growth period interval time long, and no obvious rules tofollow.