Perennial rice different distantly related perennials in the hopes that at least one of these strategies would enable genes from the perennial to be moved to the cultivated rice gene pool. Hu Fengyi, now deputy director of the Food Crops Institute at YAAS, worked on the IRRI perennial-rice project and was senior author of the paper that first reported on mapping of genes for rhizome production in rice. Using the F2 population derived from the Oryza sativa/O. longistaminata cross, two dominant-complimentary genes, rhz2 and rhz3 controlling rhizomatousness were mapped. These were found to correspond with two QTLs associated with rhizomatousness in the
Scirpophaga nivella orange anal tuft, sometimes brownish in the female. The larvae are off white with a reddish dorsal line. Major feeding plant is sugarcane, besides "Oryza sativa", "Scirpus", "Cyperus", "Eleocharis" (including "Eleocharis dulcis") and "Calidum articulatum" are also susceptible as feeding plants of the moth. Caterpillars bore into midrib, by leaving red markings and small holes on the leaves. Then it bore in the upper portion of stem, causing "dead heart" symptoms. Gradually, side branches start growing from a lower node, giving a characteristic "bunchy top" appearance to the plant. Most effective method is using biological predators and parasitoids. It is