| Seed vigor plays an important role in the agriculture production. Thehigher sowing seeds quality is required with the development of the agricultureproduction. In the seeds storage, the higher seed vigor is better able to resist all kinds ofadversity, so it’s helpful for long-term preservation of germplasm resource. In this study,201recombinants inbred lines were constructed by Yu82and Shen137, standardgermination test, low temperature germination test and artificial accelerated aginggermination test were carried out in the artificial climate chamber. A genetic map wasconstructed by SSR markers. QTL analysis for germination energy, germinationpercentage, germination index, vigor index, seedling length, seedling dry weight and rootdry weight related traits of seed vigor were conducted by composite interval mapping(CIM) method. The interaction among detected QTLs and the interaction with QTL andenvironment were analysis in different temperature environments and different agingtreatments in order to find stable effect genes or QTL, and candidate genes wereforecasted using the method of bioinformatics. The results will help for gene cloning andmarker assisted section of seed vigor. The main results were as follows:1. In total,654SSR primers were choose to screen polymorphism between Yu82andShen137,175great differences in polymorphism makers were found, and a maize geneticlinkage map contains171markers was constructed which covered10chromosomes ofmaize. The each length of chromosome is320.4,263.9,287.5,201.7,288,224.4,122.9,160.4,265.4and216cM, and the markers of each chromosome are23,17,17,19,22,16,10,14,17and16, respectively. The total genetic distance is2350.6cM with13.7cMaverage distance between markers.2.10QTLs of seed vigor were detected under the standard germination test (28℃)and low temperature germination test (18℃), which distributed on1,3,4,9and10chromosomes, the contribution of each QTL between5.6%and15.6%. The qVI3whichcontrol vigor index has a maximum contribution rate of15.6%. In standard germination,qGI1and qVI1which control germinaton index and vigor index was located in markphi039-umc2029interval and umc2029-bnlg1268interval, respectively. In the lowtemperature germination test, a common QTL which control germination index and vigorindex was detected on chromosome10in159.1cM, which in mark umc1677-umc1993interval. The germination index and vigor index can be used effective traits of seed vigorcompared to other traits of seed vigor.3.30QTLs of seed vigor were detected in the artificial accelerated aging treatments of2days,4days and6days, which distributed on1,2,3,4,5,8,9and10chromosomes,and the contribution rate between6.3%and12.6%. Stability QTL controled vigor indexwas detected in157.1cM on chromosome10, which located in markerumc1648-umc1677interval inside, can be used as a molecular marker in the molecularassistant selection. On the chromosome10, we found an important chromosome segmentsthat controled seed vigor, which located in10.04-10.06points, in umc1272-umc1993mark interval inside.After2days aging treatments, qGET2, qGIT2and qVIT2controled germinationerengy, germination index and vigor index, respectively, were located on chromosome2,in the same mark interval umc1923-umc1637inside. After4days aging treatments,qGPF10and qVIF10controled germination percentage and vigor index, respectively,were located on chromosome10, in neighboring mark interval. After6days agingtreatments, the QTLs controled germination energy, germination percentage, germinationindex and vigor index were located on chromosome10, in the same mark intervalumc1648-umc1667, may be a QTL, showed pleiotropy or tight linkage.4. Four pairs AA which influced related traits of seed vigor were detected indifferent temperature environments, they have reached a significant level. Theyperferenced a non-additive effect, but they were common for AA epistatic effect. Soepistatic effect palys an important role in seed vigor under the different temperatureenvironments. In different aging treatment conditions,11additive effect and additive×environment (AE) interaction effect QTLs were detected, and2pairs AA epistatic weredetected, which distributed on1,3,4,8and10chromosome, the contribution ratebetween2.49%~7.21%, and qGE1-3controled germination energy showed the biggestcontribution rate.On chromosome1, qGE1-3, qGR1-3, qGI1-3, qVI1-3all in the markumc1568-bnlg1007interval, within the same or similar position, it might be a gene orperformance as tight linkage, and the efficiency gene from Yu82. In umc1121-mmc0181mark interval on chromosome8, qGE8-9, qGR8-9, qGI8-9and qVI8-9controledgermination energy, germination percentage, germination index and vigor index weredetected simultaneously, and the efficiency gene from Shen137.5. In different days under the aging treatment, the parents of Yu82and Shen137perferenced different anti-aging, Yu82were better than Shen137in the aspects ofanti-aging, such as germination energy, germination percentage, germination index, andvigor index and seedling length of seed vigor. The results of QTL detected using RILsshowed that two parents had both a synergy to the related traits of seed vigor in the earlyaging treatment; however, more and more efficiency gene came from Yu82with theincrease aging time. Therefore, in the process of mading cross combination, using Yu82as parent inbred line, through some breeding method such as molercular assistant selection, cross and backcross, we can make a strong advantage of hybrid combination. |
PDF Full Text Request