Standardization of in vitro regeneration protocols from immature male flower buds of banana cv Karpura Chakkarakeli Musa AAB Mysore subgroup

Abstract

An efficient in vitro propagation method has been developed for the first newlinetime for banana cv. Karpura Chakkarakeli (AAB), an economically important newlinebanana cultivar of Andhra Pradesh, India. Due to its highly recalcitrant nature, newlineexcessive phenol compounds, biotic contamination and poor multiplication rate newlinein vitro by shoot tip explants, the potentiality of immature male flower buds were newlineexamined as an alternate source for culture establishment. Virus indexing by newlineDAC-ELISA technique effectively detected 10% cucumber mosaic virus (CMV) newlineand 7.5% banana bract mosaic virus (BBrMV) infected mother plants, which newlinewere excluded for micropropagation studies. Among the different photoperiod newline(16h: 8h) and gelling agent treatments tested to arrest the phenol ooze from the newlineinitiated immature male flower explants for culture establishment, significantly newlinethe treatments T3 and G1 recorded lowest number (4.33 and 10.29) of explants newlinephenol exuded, maximum number (15.67 and 9.71) of explants survived, lowest newlinebrowning per cent (21.67% and 51.43%) and highest survival percentage (78.33% newlineand 48.62%) of explants respectively. The established explants subjected to newlinedifferent PGRs and gelling agents for regeneration, the treatments T14 (1.0 mgL-1 newlineTDZ + 0.5 mgL-1 newlineIAA + 2 mgL-1 Casein Hydrolysate) and G1 (0.25% gelrite) newlinerecorded better results pertaining to morphogenetic responses viz., days taken newline(43.54 and 50.09d), number (15.01 and 10.23) and percentage (75.04% and 51.16%) newlinefor cauliflower-like bodies formation respectively. Per cent of explants responded newlineto induce shoots (75.37% and 53.21%), number of shoots (12.78 and 8.24) explant-1 newline, newlineshoots length (6.01cm and 5.18cm), pseudostem diameter (5.98mm and 5.24mm), newlinenumber of leaves (3.48 and 3.02), leaf area (9.49cm2 and 6.56cm2 newline) and dark green newlineleaf colour of the regenerated plantlets after 120 DAI in the similar treatments newlineT14 and G1 respectively. newlineThe optimized plant growth regulator 1.0 mgL-1 TDZ + 0.5 mgL-1 newlineIAA + 2 newlinemgL-1 Casein Hydrolysate (T9) was augmented with different organic additives