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Forty-two accessions of eggplant were screened against Ralstonia solanacearum in screen-house environments. This was followed by an assessment of the genetic diversity of the 42 eggplant successions originating from Bangladesh, China, Thailand and Malaysia, accomplished by exploring SSR markers for germplasm characterisation. Five selected resistant genotypes used as a rootstock were further assessed with UPMSE16 strain in a subsequent trial. The pathogenicity test based on area under the disease progress curve (AUDPC) and disease severity index (DSI) at four weeks after inoculation indicated that genotypes TB3, TB6, TB7, MB16 and BB9 had the greatest degree of resistance. Also, the results of the second trial for grafted and control plants based on DSI and AUDPC at 4 WAI showed that grafted plants had resistance to UPMSE16 strain with no symptoms at 4 WAI. The 42 accessions were grouped into nine major clusters based on SSR markers using Unweighted Pair Group Method with Arithmetic mean. Hence, the phenotyping screening reveals that five eggplant accessions were resistant to R. solanacearum and can be used as potential rootstock. As a result, the discovered SSR markers may be effective in marker-assisted selection for future use in developing new rootstock. [ABSTRACT FROM AUTHOR]

The first step in plant breeding is to identify suitable genotypes containing the desired genes among existing varieties, or to create one if it is not found in nature. In nature, variation occurs mainly as a result of mutations and without it, plant breeding would be impossible. In this context, the major aim in mutation-based breeding is to develop and improve well-adapted plant varieties by modifying one or two major traits to increase their productivity or quality. Both physical and chemical mutagenesis is used in inducing mutations in seeds and other planting materials. Then, selection for agronomic traits is done in the first generation, whereby most mutant lines may be discarded. The agronomic traits are confirmed in the second and third generations through evident phenotypic stability, while other evaluations are carried out in the subsequent generations. Finally, only the mutant lines with desirable traits are selected as a new variety or as a parent line for cross breeding. New varieties derived by induced mutatgenesis are used worldwide: rice in Vietnam, Thailand, China and the United States; durum wheat in Italy and Bulgaria; barley in Peru and European nations; soybean in Vietnam and China; wheat in China; as well as leguminous food crops in Pakistan and India. This paper integrates available data about the impact of mutation breeding-derived crop varieties around the world and highlights the potential of mutation breeding as a flexible and practicable approach applicable to any crop provided that appropriate objectives and selection methods are used.

Chili anthracnose is one of the most devastating fungal diseases affecting the quality and yield production of chili. The aim of this review is to summarize the current knowledge concerning the chili anthracnose disease, as well as to explore the use of marker-assisted breeding programs aimed at improving anthracnose disease resistance in this species. This disease is caused by the Colletotrichum species complex, and there have been ongoing screening methods of chili pepper genotypes with resistance to anthracnose in the field, as well as in laboratories. Conventional breeding involves phenotypic selection in the field, and it is more time-consuming compared to molecular breeding. The use of marker-assisted selection (MAS) on the basis of inheritance, the segregation ratio of resistance to susceptibility, and the gene-controlling resistance may contribute to the development of an improved chili variety and speed up the selection process, while also reducing genetic drag in the segregating population. More importantly, by using molecular markers, the linkage groups are determined dominantly and co-dominantly, meaning that the implementation of a reliable method to produce resistant varieties is crucial in future breeding programs. This updated information will offer a supportive direction for chili breeders to develop an anthracnose-resistant chili variety.