Challenges and Progresses of Molecular Plant Breeding in Crop Improvement

Temesgen Begna

doi:10.7176/jnsr/11-21-04

Abstract

Molecular marker is applicable to many aspects of plant improvement and crop production. The main objective of plant breeding to produce crops with improved characteristics with the utilization of the available genetic variability and producing sufficient genetic variability of crops by different breeding techniques. There are possibilities to improve the desired traits through conventional breeding methods in the presence of genetic diversities. However, there are several challenges to make the significant improvement on the crop through conventional breeding. Conventional breeding is almost always based on phenotypic variation of the crops, which is affected by environments (non-heritable components) and crop improvement cycle takes long time. However, molecular marker is designed to meet this challenges regardless of its cost and it’s not affected by environment where ever the experiment is conducted either in laboratory or field condition. Molecular marker procedures are playing a significant role to increase the effectiveness in breeding and shorten the development crop improvement stages. Molecular markers also used develop resistant crop to pests and diseases, develop tolerant crop to environmental conditions and improve the crop in required quality. In facing the challenge of improving several lines for quantitative traits, marker assisted selection strategies use DNA markers in one key selection step to maximize their impact. With the development of molecular marker technology, the fate of plant breeding has changed. Different types of molecular markers have been developed in identification and characterization germplasm, DNA sequences in identification of the genomic regions involved in the expression of the target traits, to analysis the genetic variation, cytogenetic, quantitative genetics, biotechnology and genomics and it’s applied in genetic diversity analysis in crop improvement. It is possible to increase agricultural productivity through addressing the problems of yield reduction and its links with pest management and climate change using advanced breeding technologies. There are several major challenges in the application of molecular markers to agronomically important traits. Some of them are: economic factors, lack of grants to researchers, lack of adequately trained personnel. Generally, the integrating molecular marker technologies with the conventional breeding strategies are increasingly important to realize genetic gains with greater speed and precision. Keywords: Molecular marker; Marker assisted breeding; quantitative traits; Plant breeding DOI: 10.7176/JNSR/11-21-04 Publication date: November 30 th 2020

Highlights

Plant breeding is primarily depends on presence of substantial genetic variation to address the maximum genetic yield potential of the crops and exploitation of this variation through effective selection for improvement
Different types of molecular markers have been developed in identification and characterization germplasm, DNA sequences in identification of the genomic regions involved in the expression of the target traits, to analysis the genetic variation, cytogenetic, quantitative genetics, biotechnology and genomics and it’s applied in genetic diversity analysis in crop improvement
The fundamental discoveries of Darwin and Mendel established the scientific basis for plant breeding and genetics at the turn of the 20th century

Summary

Introduction

The difficulties that are associated with selecting plants that express recessive alleles, genes that have only minor effects on plant phenotypes or genes whose expression is strongly modified by the growth environment are major limiting factors in plant improvement On this regard several biotechnological procedures have greatly expanded the possibilities for increasing the genetic diversity of crop species through molecular assisted selection of potential parents, tissue culture-induced variability, protoplast fusion and the production of transgenic plants (Smith and cooper, 2004). Advantages associated with randomly-amplified polymorphic DNA analysis include: (i) Use of small amount of DNA which makes it possible to work with population that is not accessible with restriction fragment length polymorphism It is fast and efficient in analysis having high-density genetic mapping as in many plant species (Kiss et al, 1993), (ii) Non-involvement with radioactive assays (Kiss et al, 1993) (iii) Non-requirement of species specific probe librararies (IV) Non-involvement in blotting or hybridization. Single nucleotide polymorphisms may fall within coding sequences of genes, non-coding regions of genes or in the intergenic regions between genes at different frequencies in different chromosome regions (Schmid et al, 2003)

AFLP High yes SNP

Findings

Conclusion