Phenotypic characterization of the novel seedling stage zebra leaf mutant, Pusa Zebra 18 in rice

A novel zebra mutant, “Pusa Zebra 18” derived spontaneously from the breeding population exhibited distinguishable yellowish cross bands across the green leaf blade, specifically expressing in the seedling stage from 6 DAT, which recovers progressively leading to complete recovery of normal green leaf by 30 DAT. The mutant PZ 18, showed a significant reduction in root traits at 6 DAT, and 15 DAT and recovered to the level of wild type by 30 DAT. At 6 DAT, content of both the photosynthetic pigments such as chlorophyll a, b, total chlorophyll, total carotenoids, and photosynthetic rate and fluorescence kinetic parameters such as F v /F m , Φ PSII , ETR, were reduced significantly in mutant leaf yellow portion, whereas green portion of mutant and wildtype leaves were on statistically par. These parameters gradually increase in the yellow portion of the mutant, PZ 18 and attains the same level as the green portion of PZ 18 and the wild type by 30 DAT. Based on detailed characterization, it was discovered that transplanting triggers the zebra trait expression in PZ 18. There was no significant difference observed between the PZ 18 and Pusa 44 for agro-morphological traits such as plant height (cm), number of tillers, panicle length (cm) and yield per plant (g) after complete recovery at 30 DAT. Further inheritance, mapping, fine mapping, cloning and functional characterization need to be carried out, which will help in gaining insight into mechanism involved in chlorophyll biosynthesis and regulation studies in rice.