Anther culture of recalcitrant indica x Basmati rice hybrids - Anther culture of indica rice hybrids

Fertile, green, di-haploid plants were obtained at high frequencies from several indica x Basmati rice F-1 hybrids and/or F-2 plant populations using an improved anther culture procedure. Anthers from cold-pretreated (10 degrees C for 10 d) panicles of six indica (HKR120, HKR86-3, HKR86-217, PR106, Gobind and CH2 double dwarf) and two Basmati rice (Basmati 370, Taraori Basmati) varieties and 14 heterotic indica x Basmati F-1/F-2 hybrids were cultured in modified agarose-solidified N6M, Heh5M and RZM media. Best callus induction frequencies (2.6-78%) were obtained in RZM medium containing 4% (w/v) maltose, 2,4-D, NAA and kinetin. F-2 plants compared to F-1 hybrids and parental rice varieties, were more responsive to anther culture. Androgenesis frequencies of 31-78% were obtained for indica x Basmati F-2 plants in RZM medium in just 30 d which are comparable to or higher than that reported for japonica rice varieties and hybrids involving japonica rice parent(s). Agarose (1.0% w/v)-solidified MS medium containing 3.0% maltose, kinetin, BAP, and NAA, induced green shoot regeneration in 0-51% of the anther-derived calli depending upon the genotype. High plant regeneration frequencies (67-337 green plants per 1000 anthers) were obtained from anther calli of several F(1)hybrids (Gobind x Basmati 370 and HKR120 x Taraori Basmati) and F-2 plants (Gobind x Basmati 370, Gobind x Taraori Basmati, HKR86-3 x Taraori Basmati). A sample of 498 plants obtained from the above hybrids, were transferred to pots with > 90% survival; 8-78% of these plants had > 5% spikelet fertility and were diploid. In addition, 18% of the haploid plants could be diploidized by submerging in 0.1% colchicine solution for 16-18 h. The improved anther culture procedure reported here, resulted in several fold increase in the recovery of green plants from recalcitrant indica x Basmati rice hybrids compared to previous published procedures. The study may accelerate the introgression of desirable genes from indica into Basmati rice using anther culture as a breeding tool.