RESUMO
Leguminous crops are important components of Indian horticulture, because of being an important source of nutrition in predominantly vegetarian diet. In order to investigate the genetic diversity present in the underutilized legume sword bean genotypes of North-Eastern hill region of India 20 native sword bean (Canavalia gladiata Jacq.) genotypes were collected from different agroclimatic region of North-Eastern hill region of India. The morphological characters were observed in days to seed germination i.e. (3-6 days), pod length (16.45-32.87 cm), pod width (2.28-4.33 cm), pod weight (17.92-31.93 g), pod girth (7.75-12.64 mm) and seed weight (0.75-2.35 g). Performance of CHF SB-1, CHF SB-18, CHF SB-11, CHF SB-19, CHF SB-15, CHF SB-4 and CHF SB-10 genotypes under test conditions was superior and suggested that breeders might exploit the genome of these genotypes in current pulse crop improvement programmes.
RESUMO
A black scab disease occurred on sword bean (Canavalia gladiata) in plastic film houses around Chinju area during the spring season of 1999. The disease started from flower bud, then moved to flower stalk, pod, petiole, cirrus, stem and leaves. The lesions started with small dark brown spots then were gradually expanded. Severely infected plants reached 37.4% of whole plant covered with scab. Numerous conidia were produced on the diseased flower disk, pod, floral axis, stem and leaves. Most of the conidia were appeared to be readily dispersed in the air, but the mycelia were not suggested causing of sooty mold by ectoparasitism. A fungus was isolated from the diseased stem, and inoculated to healthy plants to satisfy the Koch's postulates and proved the fungus was the causal agent of the disease. The isolated fungus grew on potato dextrose agar, forming greenish black to pale brown colonies. Conidia were ellipsoidal, fusiform or subspherical, mostly one-celled but occasionally septated. The conidia were 3.9~34.1x2.7~5.1microm in size and formed in long branched chains on the erected conidiophores which were pale olivaceous brown and variable in length between 7.2~210.7microm in size. Ramoconidia were 7.6~29.2x3.2~14.4microm in size. The fungus was identified as Cladosporium cucumerinum based on the above morphological characteristics. The optimum temperature for mycelial growth and conidial formation was about 15 to 25degrees C. Cladosporium scab of sword bean caused by the fungi has not been reported in Korea previously.