Length of grain affects the appearance, quality, and yield of rice. A rice long-grain chromosome segment substitution line Z744, with Nipponbare as the recipient parent and Xihui 18 as the donor parent, was identified. Z744 contains a total of six substitution segments distributed on chromosomes (Chrs.) 1, 2, 6, 7, and 12, with an average substitution length of 2.72 Mb. The grain length, ratio of length to width, and 1 000-grain weight of Z744 were significantly higher than those in Nipponbare. The plant height, panicle number, and seed-set ratio in Z744 were significantly lower than those in Nipponbare, but they were still 78.7 cm, 13.5 per plant, and 86.49%, respectively. Furthermore, eight QTLs of different traits were identified in the secondary F₂ population, constructed by Nipponbare and Z744 hybridization. The grain weight of Z744 was controlled by two synergistic QTLs (qGWT1 and qGWT7) and two subtractive QTLs (qGWT2 and qGWT6), respectively. The increase in the grain weight of Z744 was caused mainly by the increase in grain length. Two QTLs were detected, qGL1 and qGL7-3, which accounted for 25.54 and 15.58% of phenotypic variation, respectively. A Chi-square test showed that the long-grain number and the short-grain number were in accordance with the 3:1 separation ratio, which indicates that the long grain is dominant over the short-grain and Z744 was controlled mainly by the principal effect qGL1. These results offered a good basis for further fine mapping of qGL1 and further dissection of other QTLs into single-segment substitution lines.

谷物的长短会影响稻米的外观，品质和产量。鉴定了以长春花为受体亲本，西汇18号为供体亲本的水稻长粒染色体区段代换系Z744。Z744包含分布在染色体（Chrs。）1、2、6、7和12上的总共六个替换段，平均替换长度为2.72 Mb。Z744的粒长，长宽比和1000粒重显着高于日本晴。Z744的株高，穗数和结实率均显着低于Nipponbare，但仍分别为78.7 cm，13.5 /株和86.49％。此外，在次生F ₂中鉴定出八个具有不同性状的QTL。种群，由Nipponbare和Z744杂交构建。Z744的粒重分别由两个协同QTL（qGWT1和qGWT7）和两个减法QTL（qGWT2和qGWT6）控制。Z744的晶粒重量的增加主要是由于晶粒长度的增加引起的。检测到两个QTL，qGL1和qGL7-3，分别占表型变异的25.54和15.58％。卡方检验表明，长粒数和短粒数符合3：1的分离比，这表明长粒比短粒占主导地位，Z744主要受主体的控制。效果qGL1。这些结果为进一步更好地映射qGL1和将其他QTL进一步分解为单段替代系提供了良好的基础。