Evaluation of some faba bean genotypes against chocolate spot disease using cDNA fragments of chitinase gene and some traditional methods.

摘要

Thirteen faba bean (Vicia faba L.) genotypes were assessed under greenhouse and field conditions in 2008/2009 and 2009/2010 seasons, using morphological and molecular characterization methods for resistance to chocolate spot diseases caused by Botrytis fabae A significant variation among the tested genotypes and their reaction to the disease was found under greenhouse condition. Sakha 1, 2 and Nubaria 1 were resistant, indicating by the lowest disease severity. Whereas, Giza 40, line 375 and Cairo 25 were susceptible. Other faba bean genotypes were moderately susceptible. RT-PCR analysis using chit 1 and 2 primers amplified fragment of chitinase gene (900 bp) in six faba bean genotype upon infection with the pathogen 48 h after inoculation. This fragment detected only in the resistance cultivars Sakha 1, 2 and Nubaria 1 and some moderate resistance genotype including Giza 3, line 24 H and line 36. At the same time no signal was detected in other infected genotypes or healthy ones. Field results of testing genotype against chocolate spot diseases often do not correspond completely with greenhouse results since the environment is less controlled and possibly natural infection could introduce unwanted pathogen(s) or other factors. The estimates of heritability in broad sense ranged from 0.90-0.99, high values of heritability were obtained for seed yield/plant (0.99), followed by plant dry weight, plant height, seeds pod-1 across the two seasons. However, No relationship was found between resistance of genotypes against B. fabae and their morphological characterizes under field conditions.CAS Registry Numbers 9001-06-3