A Study of the effects of powdery mildew erysiphe raminis F SP avenae on the growth and development of wild and cultivated oats

Voir Plus Voir Moins

Afficher le Résumé

Thesis presented for the degree of doctor in phylosophy in the faculty of science at the university of glasgow. department of botany, university of glasgow. 22nd april 1993. resistant cultivars have generally been very successful in limiting crop josses caused by many fungal parasites. their use controls the genetic composition of the host population with which the parasite population must interact, and by restricting the ability of the parasite population to grow and reproduce enables the host to continue growth longer so that its yielding capacity is less impaired . the commonest means of controlling plant parasites by resistance breeding has been through the use of major genes. in a few cases, major gene resistance has given lasting protection. for example, potato wart disease caused by synchytrium endobioticum has been successfully controlled for many years through the use of resistant cultivars in most countries where potatoes are grown (burton, 1989). cultivars of tomato possessing a race-specific resistance gene against nailhead spot, a fruit, stem and leaf spot disease caused by alternarlia tomato have been used to give good disease control (crill, 1977). some of the older english and french wheat varieties showed a good resistance for many years to the yellow rust caused by puçcinia striiformis until they were superseded by higher yielding varieties. for example, little joss, a winter wheat variety bred at cambridge by biffen (1907) was reported to be as resistant to yellow rust in the 1950's as when it was first bred. innes (1974) reported that bacterial blight of cotton in the sudan caused by xanthomonas malvacearum was greatly reduced, and even almost eliminated by the use of resistant cultivars.