Search

The article discusses a study on near isogenic lines of the silkworm, Bombyx mori for identification of random amplification of polymorphic DNA (RAPD) markers linked to digestive amylase genes. Primers were used for the study out of which six showed RAPD products linked to the amylase genes of the Donor Parents introgressed in the Near Isogenic Lines. The results are discussed for identification of DNA sequences that may be responsible for better digestibility and higher survival is discussed.

Mulberry (Morus sp.) is extensively cultivated for rearing silkworms (Bombyx mori L.) for production of silk. As the mulberry leaf is rich in nutritive value with 22-24% protein, the studies on its use other than silkworm rearing are gaining importance in recent years. To utilize the mulberry leaf for alternative purposes other than silkworm rearing, a study for utilizing mulberry as a poultry feed supplement was conducted at CSRTI, Mysore. Broiler chicks (Breed: COB-400) were raised on four different test rations supplemented with different levels of mulberry leaf powder viz., 0 (control), 5, 10, 15 and 20% and data on initial body weight, final body weight, feed consumption, etc., were recorded. The results revealed that the highest mean body weight after the growth period of six weeks was recorded in 10% supplementation. The highest feed consumption per bird was in control followed by 5, 10, 15 and 20%. The maximum feed conversion ratio at six weeks of growth was in 10%, suggesting that the mulberry leaf powder supplementation at 10% would cut down the cost of poultry feed. This is the first report on this aspect in India, which would benefit the poultry farmer in economizing the cost of meat production. [ABSTRACT FROM AUTHOR]

The pre-penetration and infection process of Colletotrichum dematium on mulberry leaf was investigated by scanning electron microscope. Conidia produced on germination appressoria directly or at the end of short germ tubes. Appressoria were formed mostly over cuticle, but sometimes over stomata also. At 72 h post-inoculation, an extensive network of sub-cuticular runner hyphae (RH) was produced. The RH were traceable by the cuticular bulgings on leaf surface. The RH emerged to leaf surface through ruptured cuticle to form secondary infection hyphae (SIH). The SIH re-entered the leaf tissue by sending penetration branches through stomata. Conidia were formed singly on short conidiophores from the RH and SIH, at short intervals. The conidia developed on RH were exposed to leaf surface through ruptured cuticle. Some times conidia were released through stomata also. The RH and SIH had thick knots from which hyphal branches and conidia were developed. Definite acervuli were not developed. [ABSTRACT FROM AUTHOR]