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

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.

Androgenesis in indica rice: A comparative competency in development of doubled haploids

“…Androgenesis has been utilized to develop a number of rice varieties and improved breeding lines mostly in japonica cultivars [ 18 ]. However, indica cultivars was found to be recalcitrant to tissue culture including anther culture which hinders the success in rice improvement [ 19 , 20 ]. Anther culture is of two steps: the first step involves the induction of calli from microspores and the next step deals with the regeneration of green plants from the calli [ 21 ].…”

Genetic variation of doubled haploids derived from anther culture of M1 red rice plants

“…The onset and frequency of callus initiation is widely known as genotype dependent. It can be improved by adjusting culture media with different combination ratio of auxin and cytokinin (Rahman et al 2021), modified basal media (Ali et al 2021), or supplementing with polyamines (Maharani et al 2020). The present study suggested that gamma irradiation treatments indirectly could increase callus formation.…”

“…The percentage of anthers producing callus increased with increasing irradiation dose which was 3.33%, 4.33%, 5.00%, and 5.67% at doses of 0, 100, 200, and 300 Gy, respectively (Table 1). In other studies, the percentage of callus induction of Indica rice cultivars was relatively in a similar range of 2.30%-8.45% (Ali et al 2021;Rahman et al 2021). Cempo Abang is classified as the Indica subspecies, which is known as more recalcitrant to callus induction in-vitro than the Japonica subspecies.…”

Callus induction and regeneration in high-altitude Himalayan rice genotype SR4 via seed explant

“…Six Asian countries use over 89 percent of world rice produce viz., Bangladesh, Japan, China, Vietnam, Indonesia and India [36] . Rice is presently planted in over 100 nations, with a combined harvested area of around 158 million ha and about 470 million tonnes of processed rice generated [5] . To sustain the predicted 8.6 billion world population until 2030, yearly rice output of 756 million metric tonnes (MMT) is necessary to ensure food supply [10] .…”