Improved Anther Culture Media for Enhanced Callus Formation and Plant Regeneration in Rice (Oryza sativa L.).

Jauhar Ali,Azerkhsh Torabi,Corinne M Marfori-Nazarea,Shahana Akther,Ali Akbar Ebadi,Katrina Leslie C Nicolas,Anumalla Mahender

doi:10.3390/plants10050839

Abstract

Anther culture technique is the most viable and efficient method of producing homozygous doubled haploid plants within a short period. However, the practical application of this technology in rice improvement is still limited by various factors that influence culture efficiency. The present study was conducted to determine the effects of two improved anther culture media, Ali-1 (A1) and Ali-2 (A2), a modified N6 medium, to enhance the callus formation and plant regeneration of japonica, indica, and hybrids of indica and japonica cross. The current study demonstrated that genotype and media had a significant impact (p < 0.001) on both callus induction frequency and green plantlet regeneration efficiency. The use of the A1 and A2 medium significantly enhanced callus induction frequency of japonica rice type, Nipponbare, and the hybrids of indica × japonica cross (CXY6, CXY24, and Y2) but not the indica rice type, NSIC Rc480. However, the A1 medium is found superior to the N6 medium as it significantly improved the green plantlet regeneration efficiency of CXY6, CXY24, and Y2 by almost 36%, 118%, and 277%, respectively. Furthermore, it substantially reduced the albino plantlet regeneration of the induced callus in two hybrids (CXY6 and Y2). Therefore, the improved anther culture medium A1 can produce doubled haploid rice plants for indica × japonica, which can be useful in different breeding programs that will enable the speedy development of rice varieties for resource-poor farmers.

Highlights

callus induction frequency (CIF) and regeneration of green plantlets (RGP) in different rice subspecies. This present study aims to improve anther culture efficiency in terms of callus formation and plant regeneration by using modified N6 [56] medium compositions, which were designated as Ali-1 (A1) and Ali-2 (A2) in five rice genotypes belonging to different subspecies
Anther culture technique is a biotechnology tool that has found importance and a niche in expediting many crop breeding processes. In rice this technology was highly limited to japonica rice types because of the recalcitrant nature of many indica rice types
Two improved anther culture media were evaluated based on their ability to enhance the callus formation and green plant regeneration of five rice genotypes that belonged to different subspecies, which have varied anther culture responses

Summary

Introduction

Rice is one of the major staple food crops for more than 3.5 billion people who rely on this crop for almost 20% of their regular calorie intake To feed the estimated 8.6 billion global population by 2030, 756 million metric tons (MMT) of annual rice production are required to provide food security [3]. Rice is grown in more than 100 countries, with a total harvested area of approximately 158 million hectares, and approximately 470 million tons of produced milled rice (http://ricepedia.org/rice-as-food/rice-productivity/, accessed on 15 June 2020). To ensure the food security of the rapidly growing global population, rice production must be increased to 852 million tons by 2035 [4]. There is an urgent need to develop climate-smart rice cultivars with multiple biotic and abiotic stress tolerance through the use of advanced biotechnological tools and modern conventional breeding approaches

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