Diversity of Rice Varieties and Cropping Systems in Bangladesh Deepwater Area
Sixty-eight indigenous rice cultivars collected in deepwater areas in Bangladesh were examined in terms of heading behavior and allozyme variation. Seasonal ecotypes differed in the heading behavior for adaptation to their respective cropping seasons. Isozyme analysis revealed that cultivars grown in deepwater areas in Bangladesh consisted of a Japonica-like group and unclassified unique group in addition to a major Indeca group. Classification by isozyme variation was not necessarily consistent with the differentiation into seasonal ecotypes. Cultivars collected in a restricted area in Khulna District consisting of various seasonal ecotypes showed a genetic similarity to each other, suggesting that geographical differentiation preceded seasonal differentiation. Based on a case study conducted in 2 villages in Khulna, it was pointed out that diverse landraces which are adapted to different local and seasonal conditions have evolved by interacting with traditional planting systems.
|作成者||Hong-Wei CAI Hiroko MORISHIMA|