Control of phoma stem canker in oil rapeseed crops typically depends on cultivars resistant to L. Maculans, the virus that causes it. Recently, virus populations have overcome resistance, causing serious canker outbreaks in Australia and Europe. There is an urgent need to find sources of resistance to L. maculans. This book synthesizes studies in management of resistance genes control L. maculans, and will stimulate further research on this important model system.
Control of phoma stem canker in oil rapeseed crops typically depends on cultivars resistant to L. Maculans, the virus that causes it. Recently, virus populations have overcome resistance, causing serious canker outbreaks in Australia and Europe. There is an urgent need to find sources of resistance to L. maculans. This book synthesizes studies in management of resistance genes control L. maculans, and will stimulate further research on this important model system.
This book presents an unprecedentedly thorough collection of information on the diseases of cultivated annual oilseed crops, including peanut, rapeseed-mustard, sesame, soybean, sunflower, and safflower. It covers and integrates global literature on the subject up to 2014, setting it apart from other books that are only of regional importance. The authors are internationally recognized experts who have compiled decades of information from previously scattered research into a single volume that provides much-needed updates to oilseed crop disease research.
Canola (oilseed rape, Brassica napus L.) is a cash crop grown in different countries including Canada, the European Union, China and Australia. The production of this crop is threatened by blackleg disease caused by the fungus Leptosphaeria maculans (Desm.) Ces. & De Not. [anamorph: phoma-like (de Gruyter)]. In order to develop a more effective disease management strategy; there is a need to employ crop rotation, introgress new resistance (R) genes into elite cultivars, test the effectiveness of existing R genes, and predict the emergence of virulent isolates of L. maculans. In this study, sequenced characterised amplified region (SCAR) and derived-cleaved amplified polymorphic sequence (dCAPS) markers linked to the L. maculans resistance gene Rlm6 were developed and their segregation was confirmed by analysis of F2 and F3 progeny. In addition, chromosomal segment substitution lines (CSSLs) harbouring Rlm6 were developed through a combined approach of classical and marker-assisted backcross breeding. The field study suggested a potential effectiveness of a 2-year crop rotation, because of the reduction of disease severity at the end of the 4-year trial. By the end of the study, the R genes LepR1, LepR3, Rlm2, and Rlm4 were effective against L. maculans, whereas Rlm3 was moderately effective. Linear regression analysis suggests an order of effectiveness among the R genes tested: LepR3 > LepR1> Rlm2 > Rlm4 > Rlm3. Moreover, the decreased frequency of effector genes AvrLm2 and AvrLm4 in L. maculans isolates suggested the gaining of virulence toward Rlm2 and Rlm4 within a year. Results from sequencing of the AvrLm2 gene revealed a shift of AvrLm2 to avrLm2 allele due to the accumulation of point mutations. Overall, CSSLs and DNA markers developed in this study may facilitate breeding B. napus varieties resistant to L. maculans in the future. It is predicted that rotation of Rlm2, Rlm3, Rlm4, and Rlm7 could be an opportunity to increase the effectiveness of those R genes under a 2-year crop rotation. However, these studies also suggest development of generic epidemiological models for the occurrence of complex molecular interactions in B. napus-L. maculans pathosystem, allowing plant breeders to select appropriate R genes in the proposed cultivar rotation strategies on the Prairies.
Throughout their life, plants interact with all sorts of microbes. Some of these are detrimental and cause disease; some interactions are mutually beneficial for both partners. It is clear that most, if not all, of the interactions are regulated by highly complex checks and balances sustained by signalling and exchange of messengers and nutrients. The interactions where both partners are alive for a significant part of their time together are called biotrophic. In this e-book we bring together 33 articles representing the current state-of-the-art in research about diverse biotrophic plant-microbe associations aimed at describing and understanding how these complex and ubiquitous partnerships work and ultimately support much of the land-based biosphere.
Breeding Oilseed Crops for Sustainable Production: Opportunities and Constraints presents key insights into accelerating the breeding of sustainable and superior varieties. The book explores the genetic engineering/biotechnology that has played a vital role in transforming economically important traits from distant/wild species to cultivated varieties, enhancing the quality and quantity of oil and seed yield production. Integrated nutrient management, efficient water management, and forecasting models for pests diseases outbreaks and integrated pest and pest management have also added new dimensions in breeding for sustainable production. With the rise in demand, the scientific community has responded positively by directing a greater amount of research towards sustainable production both for edible and industrial uses. Covering the latest information on various major world oil crops including rapeseed mustard, sunflower, groundnut, sesame, oilpalm, cotton, linseed/flax, castor and olive, this book brings the latest advances together in a single volume for researchers and advanced level students. Describes various methods and systems to achieve sustainable production in all major oilseed crops Addresses breeding, biology and utilization aspects simultaneously including those species whose information is not available elsewhere Includes information on modern biotechnological and molecular techniques and production technologies Relevant for international government, industrial and academic programs in research and development
