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

Abstract

Rice is critical to global food security which demands immediate attention to meet the ever-growing population. Development of improved variety is the major focus area of research, in which doubled haploid (DH) technology plays a vital role. Since, androgenesis shows its potential in DH production, this method was not capitalized specially in indica rice due to due to its recalcitrant nature to tissue culture. Success of androgenesis is governed by many important factors such as stage of anther, pre-treatment conditions, accurate concentrations of media, and plant growth regulators. Though reports of androgenesis are abundant in rice, most of them either used japonica or a specific cultivar of indica rice ecotypes. In this study, a media combination was established which is successful in producing doubled haploids from F1s of Savitri x Pokkali, IR20 x Mahulata along with the popular indica hybrids of Arize 8433DT, Arize 6453, Arize Bold, and Swift Gold. Out of 12 different media combinations tested, and 5 different durations of cold-treatments studied, N6 media with 2,4-D (2.0 mg/l) and BAP (0.5 mg/l) with 7th day cold pre-treatment was found to be most effective in all of the F1s for callus induction. Among all the F1s, rice hybrid, Arize 8433DT showed highest of 52% callus induction. In case of green shoot regeneration, MS media with NAA (0.5 mg/l), BAP (2.0 mg/l) and Kn (1.0 mg/l) (MS+C4) was found to be the most efficient of six treatments studied with highest of 58.25% regeneration in Arize 8433DT. Further, MS+C4 in combination with proline (5.0 mg/l) increased the regeneration rate to 85.99%. Besides, MS media with NAA (1.0 mg/l), Kn (0.1 mg/l) and 50 g/l sucrose was found to be most efficient for supporting root induction in all F1s. This study claims the establishment of genotype independent androgenic protocol for indica rice which could be capitalized in indica rice improvement.

RNASeq data from Indonesian recalcitrant and non-recalcitrant rice varieties on anther culture

“…The pregnant stage was used to harvest the rice panicles of Tarabas, IR64, and Fatmawati. As part of the cold temperature pre-treatment, panicles were cleaned, wrapped in paper towels wet with water, placed in a zip-lock plastic bag, and kept at low temperatures for seven days [1] . Additionally, panicles were chosen so that the anthers would be in the uninucleate microspore growth stage when they were used as samples.…”

Development of In Vitro Anther Culture for Doubled Haploid Plant Production in Indica Rice (Oryza sativa L.) Genotypes

“…The N6 basal medium is the most generally used medium for the induction of rice androgenesis [13,[30][31][32], while Ali et al reported the superiority of the Ali-1 induction medium compared to N6 medium in AC of rice [28]. The present study compared the N6NDK induction medium to Ali-1 and N6 basal medium supplemented with combinations of different growth regulators (N6NDZ).…”

“…influence the efficiency of AC. In the indica rice, the most frequently applied basal medium was the N 6 medium [13,[30][31][32], but some other media (Ali-1, CIM) were also used for the induction of in vitro androgenesis in AC [28,29,33]. In the induction of androgenesis in rice, maltose is the most frequently applied carbohydrate source due to its positive effect on increasing callus induction and green plantlet regeneration [12,13,20,21].…”

“…In the induction of androgenesis in rice, maltose is the most frequently applied carbohydrate source due to its positive effect on increasing callus induction and green plantlet regeneration [12,13,20,21]. Exogenous growth regulators, such as 1-naphtylacetic acid (NAA), 6-benzylaminopurin (BAP), 2,4-dichlorophenoxyacetic acid (2,4-D), kinetin, zeatin and their combinations, were applied for androgenesis induction of indica rice genotypes [13,23,[28][29][30]32,33]. The development of microspore-derived calli was tracked from the initial cell division of uninucleate microspores until the callus formation in the indica rice genotype (At303) by Mayakaduwa and Silva [13].…”

“…According to published protocols, different combinations of growth regulators (BAP, NAA, kinetin and zeatin) were successfully applied to produce green plantlets and increase plant regeneration efficiency [5,7,8,[10][11][12][13][14][21][22][23][24]26,27,30,31,34,35]. The efficiency of green plantlets production was improved further by the increased quantity of gelling agent and added proline to the regeneration medium in rice AC [30,36].…”