Review Paper on Approaches in Developing Inbred Lines in Cross-Pollinated Crops

Abstract

Abstract:Plant breeding aims to constantly develop crop cultivars with improved yields and quality and tolerant to droughts, diseases and pests. Use of genetically improved crop cultivars and better management practices are among the best strategies to increase food production and meet a projected doubling of food demand. Inbred lines are homozygous genotypes produced by repeated selfing with selection over several generations. It is developed and maintained by repeated selfing of selected plants. In cross-pollinated species with strongly expressed self-incompatibility, various techniques are used to overcome the incompatibility. The technique of doubled haploids may be used to produce complete homozygous diploid lines in just 1 year (versus more than 4 years in conventional breeding) by doubling the chromosome complement of haploid cells. Doubled haploidy is and will continue to be a very efficient tool for the production of completely homozygous lines from heterozygous donor plants in a single step. Haploids contain half the chromosome number of somatic cells. Anthers/stigma Contain immature microspores or pollen grains with the haploid (n) chromosome number. If successfully cultured (anther culture), the plantlets resulting will have a haploid genotype. To have maximum genetic variability in the plantlets, breeders usually use anthers from F1 or F2 plants. Usually, the haploid plant is not the goal of anther culture. Rather, the plantlets are diplodized (to produce diploid plants) by using colchicine for chromosome doubling. This strategy yields a highly inbred line that is homozygous at all loci, after just one generation.

Hybrid Rice Production: A Worldwide Review of Floral Traits and Breeding Technology, with Special Emphasis on China

“…The process of developing hybrid rice by conventional breeding approaches involves manually cross-pollinating two or more inbred rice lines that possess desirable qualities ( Figure 1 ), which results in the production of hybrid offspring with superior attributes [ 30 ]. These inbred lines are typically developed through several generations of self-pollination to create genetically stable lines that breed true [ 52 ]. The resulting hybrid offspring often exhibit heterosis or hybrid vigor [ 53 ].…”

Exploiting phenotypic and genotypic diversity against Colletotrichum truncatum in chilli hybrids developed using resistant breeding lines

“…Homozygous parent lines are used as parents in the production of hybrid varieties. Qualities of the hybrid varieties depend on these parent lines (Shuro, 2017). Efforts have been taken to develop chilli hybrids against anthracnose using the parent lines with anthracnose disease resistance (Ridzuan, 2018).…”