控制水稻叶片叶绿素含量及其离体叶片叶绿素降解速度相关的QTL定位(简报)

MAPPING OF QTLS CONTROLLING LEAF CHLORPHYLL CONTENT AND CHLORPHYLL DEGRADATION SPEED OF DETACHED LEAVES IN RICE

许多研究认为，在一定范围内，叶绿素含量与光合速率成正相关关系、叶绿素含量高的水稻叶片能延缓衰老。理论上推算，水稻叶片如果推迟1天衰老，可使水稻增产2％左右，而实际实验结果表明可增产1％左右。叶片早衰往往也是造成有些水稻品种结实率偏低、空秕率较高及产量降低的主要原因。叶片衰老是水稻发育过程中的生命现象，它是水稻在长期进化过程中形成的适应性。叶片衰老的显著特征之一是叶绿素含量下降，叶色褪绿变黄。

A recombinant inbred （RI） population derived from the cross between an indica variety, IR24, and a japonica variety, Asominori, was used to map QTLs controlling leaf chlorophyll content（LCC） and chlorophyll degradation speed （CDS） of detached leaves collected at the tillering stage of rice through composite interval mapping analysis （CIM）. Resultantly, four QTLs （qLCC-3, qLCC-5, qLCC-7, qLCC-12） controlling LCC and three QTLs （qCDS-1, qCDS--6, qCDS-7） associated with CDS were detected respectively. Among them, qCDS-7 with the largest effect for CDS, located on chromosome 7, coincided with the genomic region of qLCC-7 for LCC detected. Those results from this study basically can explicate the genetic basis associated with leaf chlorophyll content and chlorophyll degradation speed of detached leaves in rice, which might be available for a rapid determination of leaf senescence at early growth-stages and breeding of high-photosynthetic efficiency in rice.