| Chlorophyll is the important pigment involved in photosynthesis in plant chloroplasts. When the gene regulating development and metabolism of chlorophyll mutates, the leaf color of plant will change correspondingly. Chlorophyll deficient mutation is also called leaf color mutation. In rice, leaf color mutation consists of eight classes on the basis of their phenotypes:albina, xanthan, virids, jade-white, green-white, yellow-green and striata. Chlorophyll-deficit mutants not only play an important role in studying the photosynthesis, biosynthesis of chlorophyll, genetic differentiation and development of chloroplast, but also serve as a marker to kick out false hybrids in utilizing rice heterosis. In this paper, a rice green-revertible albino mutant zjw has been studied and following conclusion could be drawed out:1) In mutant, the white-color emerged in the 3-leaf-stage of seedling. After the appearance of the forth leaf, the first three leaves gradually turned green just as normal plant. The mutant had low seed setting rate at maturity.2) The contents of chlorophyll a, chlorophyll b and carotenoid in the 2-leaf-stage of zjw were 13.93%,19.36% and 28.34% comparing to those of wide type. However, the difference of pigment content was declined to 69.88%,55.53%, and 69.70% respectively in the 4-leaf-stage.3) With the temparature changing from 23℃,26℃to 30℃, the severity of whitish leaves was weaken attributed to the increasing of chlorophyll a, chlorophyll b and carotenoid content.4) The genetic analysis to the zjwxzhong9B F2 segregating population indicated zjw is a recessive mutant of single gene.5) The gene zjw was located between BH-7 and BH-8 on rice chromosome 5 at the interval of 1500kb physical distances. At that region, no leaf-colour gene has been reported and suggested. So the gene zjw may be a novel albino green-revertible gene in rice. |
