Characterization,inheritance, and molecular study of opaque leaf mutant in mungbean (<Emphasis Type="Italic">Vigna radiata</Emphasis> (L.) Wilczek)

Chlorophyll-deficiency mutants are useful as genetic markers and as materials for studying the photosynthesis process. We characterized the inheritance of the gene controlling an opaque leaf (OL) trait in mungbean (Vigna radiata (L.) Wilczek). An F₂ population was developed from the cross between the OL mutant and ‘Berken’, an Australian mungbean cultivar, to study inheritance and molecular tagging. The population was advanced by selfing to produce F₅ lines from which two normal lines and two OL lines were randomly chosen to study chlorophyll content, seed growth and development, and seed cell morphology. The chlorophyll content in opaque leaf was lower than normal and thus was expected to have lower photosynthetic activity. This resulted in yellowish and shrinking pods and seeds within 15 days after flowering, while those from normal plants extended their growth up to 18 days. The cotyledon transfer cells of the OL plants deformed at 12 days and deteriorated at 14 days after flowering. The OL trait was controlled by a single recessive ol gene which was independent from the genes controlling petiole color and growth habit. We used 193 AFLP primer combinations to tag this gene and found that the marker AGG/ATA was linked with the ol gene at a distance of 3.4 cM.