Molecular breeding

About: Molecular breeding is a research topic. Over the lifetime, 2120 publications have been published within this topic receiving 56908 citations.

Insect resistance in Rice (Oryza sativa L.): overview on current breeding interventions

Abstract: Breeding for insect resistant varieties has been central to the integrated pest management as it offers an ecologically viable approach agianst biotic constraints. Considerable progress has been made in the past to incorporate resistance to insect pests of rice using conventional breeding approaches. However the diversity in insect pest population, continuous selection of virulent biotypes, lack of resistance sources in cultivated rice (Oryza sativa and O. glaberrima) gene pool, want of efficient insect rearing and varietal screening protocols and inherently complex genetics of resistance further necessitates supplementation of conventional breeding techniques with advanced molecular approaches. Hence, alternative approaches like wide hybridization to introgress resistance from other species of Oryza, transgenic approach to deploy Bt cry, snowdrop lectin and other plant derived genes are being actively pursued. The increasingly identified, mapped, cloned and characterized quantitative trait loci and genes related to insect resistance traits in rice have provided a solid foundation for direct selection and varietal improvement through molecular breeding. Utilization of DNA-based markers provided additional impetus to efficiency and precision of conventional plant breeding via marker-assisted selection to successfully introgress several genes for resistance to insect pests of rice. RNA interference technology has offered another reliable tool in meeting the challenges imposed by crop insects by targeting the enzymes/proteins integral to various biological processes of crop insects. This review briefly discusses the current progress and future prospects in molecular breeding for enhanced varietal tolerance to insect pests of rice.

Genomics-Aided Breeding for Climate-Smart Traits in Faba Bean

Abstract: Faba bean (Vicia faba L.) is an important pulse crop, which provides useful source of protein for human and animal consumption. The faba bean cultivation area around world has been slightly decreased due to the lack of cultivars adaptable to various biotic and abiotic stresses effects of which tend to gradually increase as consequences of climate change. Breeding for improved faba bean with biotic and abiotic stress tolerance will maintain and increase the cultivation area of faba bean by producing new cultivars having high tolerance to these stresses combined with high yield. Climate-smart traits (CSTs) can be used to evaluate faba bean genotypes for stress tolerance and to select the true promising genotypes for target traits. Moreover, the advances in genetic research in faba bean should be exploited in accelerating breeding programs to genetically improve CSTs. Unfortunately, the progress of molecular breeding research is slow due to the complexity of faba bean genome and few studies, compared to those reported in other important crops (e.g., wheat, maize, etc.), have been conducted to detect quantitative trait loci (QTLs) controlling CSTs. This chapter sheds light on the recent breeding research for CSTs in faba bean. The most important QTLs controlling CSTs detected by QTL mapping and genome-wide association study (GWAS) methods and promising validated QTL have been discussed. Moreover, an overview in faba bean genome sequencing and gene annotation for candidate genes controlling CSTs has been presented.

Transcription factor TaWRKY51 is a positive regulator in root architecture and grain yield contributing traits

Abstract: Wheat is one of the staple food crops. The utilization of elite genetic resources to develop resource-efficient wheat varieties is an effective approach to deal with the challenges of climate change and population growth. WRKY transcription factors (TFs) are multifaceted regulators of plant growth and development and response to environmental stress. The previous studies have shown that TaWRKY51 positively regulates the development of lateral roots, while its roles in agronomic trait development are not clear, and there is no functional marker for molecular breeding. To bridge the gap, we cloned the three members of TaWRKY51 and found they were highly expressed in the roots and flag leaves at the flowering stage and were induced by the multiple abiotic stresses and phytohormones. The highest expression level was observed in TaWRKY51-2D, followed by TaWRKY51-2A and -2B. The two haplotypes/alleles for each member were identified in the natural populations, and functional markers were developed accordingly. The association assays revealed that Hap-2A-I was an elite haplotype for the large spike, Hap-2B-II and allele-G were favorable haplotypes/alleles for long root. However, only Hap-2A-I was selected for wheat breeding in China. The results of transgenic experiments showed that the rice lines overexpressing TaWRKY51 had large panicle, high thousand-grain-weight, and more crown and lateral roots, which further confirmed the results of association analysis. In short, TaWRKY51 is a positive regulator of the root architecture and grain yield (GY) contributing traits. The elite gene resources and functional markers may be utilized in the marker-assisted selection for high-yield breeding in wheat.