基于SNP标记玉米种子活力相关性状研究及发芽势、发芽率QTL分析

发布时间：2018-11-27 09:27

【摘要】：国以农为本,农以种为先。种子作为一种重要的、活的、特殊的商品,在以农业为基础、玉米为重要粮食作物的中国,具有无法取代的作用。种子活力是种子质量的重要综合性指标,在玉米种用价值方面起到了关键作用,其高低直接影响到玉米产量及质量。过去,育种家往往根据玉米田间表现和子粒品质优劣选育品种,不重视与种子活力相关性状发芽力的选择,常出现一些产量和品质表现优良的品种,常因种子活力差造成缺苗断垄而减产,影响这些品种的大面积推广。因此,研究种子活力的遗传规律,对玉米品种的改良和增产增收,特别是单粒精量播种广泛应用的今天,具有重要的理论和现实意义。本研究以低活力玉米自交系12-156与高活力玉米自交系PH4CV为基础材料,杂交并通过玉米DH技术构建175份DH系,以SNP分子标记技术,在标准(常温)发芽和低温发芽条件下,定位发芽势与发芽率QTL位点。本试验主要获得的成果如下:1.标准发芽条件下,自交系12-156在10项种子活力性状的表现均低于自交系PH4CV的表型表现;低温发芽条件下,自交系12-156苗鲜重高于PH4CV,其余9项指标自交系PH4CV高于自交系12-156。所育成的DH系,在标准发芽条件下,10项种子活力性状指标均值均介于父母本之间;低温发芽条件下苗干重、苗鲜重、苗长和发芽势等4项种子活力性状指标的均值均超过双亲,表现为超亲本现象。2.利用56KSNP芯片进行基因型分析,筛选后保留5077个SNP的玉米遗传连锁图,覆盖玉米10条染色体,图谱总长度1366.98cM,标记平均距离0.27cM。3.标准发芽条件下,对发芽势QTL定位,共检测到4个QTL,分布在第1、6和7染色体上,检测到的主效QTL为2个(qsgp2和qsgp1),1个(qsgp3),1个(qsgp4);所解释的表型变异分别为17.25%和16.04%、8.65%和10.86%。低温胁迫条件下,对DH群体的发芽势进行QTL定位,共检测到1个QTL(qltgp1),位于第10染色体上,所解释的表型变异为6.67%。4.标准发芽条件下对发芽率QTL定位,未检测到QTL;低温胁迫条件下对发芽率QTL定位,共检测到1个QTL(qltgr1),位于第6染色体上,所解释的表型变异为7.75%。
[Abstract]:The country is based on agriculture, and farming is the first. As an important, living and special commodity, seed plays an irreplaceable role in China, which is based on agriculture and corn as an important food crop. Seed vigor is an important comprehensive index of seed quality, which plays a key role in maize seed use value, which directly affects the yield and quality of maize. In the past, breeders used to select varieties based on their field performance and grain quality. They did not attach importance to the selection of germinating ability related to seed vigor, and some varieties with good yield and quality often appeared. Because of the lack of seedling and ridging, the seed vigor often reduces the yield, which affects the popularization of these varieties in a large area. Therefore, it is of great theoretical and practical significance to study the genetic law of seed vigor for the improvement of maize varieties and the increase of yield and income, especially for the wide application of single seed precision seeding today. In this study, the low vigor maize inbred line 12-156 and the high vigor maize inbred line PH4CV were used as the basic materials, and 175 DH lines were constructed by maize DH technique. SNP molecular marker technique was used to germinate under standard (normal temperature) and low temperature germination conditions. Location of QTL site of germination potential and germination rate. The main results of this experiment are as follows: 1. Under standard germination conditions, inbred lines 12-156 showed lower phenotype than inbred lines PH4CV in 10 seed vigor traits. Under the condition of low temperature germination, the seedling fresh weight of inbred line 12-156 was higher than that of inbred line 12-156 in other 9 indexes of PH4CV,. Under the standard germination condition, the average values of the 10 seed vigor traits of the DH lines were between parents. The mean values of seedling dry weight, seedling fresh weight, seedling length and germination potential were higher than those of their parents under low temperature germination condition. 2. The genetic linkage map of 5077 SNP was retained by 56KSNP microarray, covering 10 chromosomes of maize. The total length of the map was 1366.98 cm, and the average marker distance was 0.27cM.3. Under the standard germination condition, four QTL, were detected on chromosome 1, 6 and 7, and the main QTL detected were 2 (qsgp2 and qsgp1), 1 (qsgp3) and 1 (qsgp4). The phenotypic variations explained were 17.25% and 16.04%, 8.65% and 10.86%, respectively. Under low temperature stress, the germination potential of DH population was mapped by QTL, and a QTL (qltgp1) was detected, which was located on chromosome 10. The phenotypic variation explained was 6.67g. 4. One QTL (qltgr1) was detected on chromosome 6, and the phenotypic variation was 7.7575.
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S513

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