Diversity in bulb traits in onion germplasm collected from Chhattisgarh and Maharashtra

Abstract

Onion germplasm was collected from Chhattisgarh (Bastar Plateau) and Maharashtra (central eastern Vidarbha region) in Peninsular India during May 2009 in collaboration with Directorate of Onion and Garlic Research, Pune and Indira Gandhi Agricultural University, Jagdalpur to assess the diversity in bulb traits for their potential utilization in onion improvement. Ninety-two samples (bulbs-91; seeds-1) were collected from 25 villages and 15 mandals. Wide range of variation was observed for bulb shape, colour and size, number of hearts and total soluble solids. Majority of the accessions possessed globe (32%), thick flat (24%) and ovate (23%) shapes. Major colours obtained were dark red (56%), light red (27.4%) and white (13.2%). Bulb weight showed maximum diversity, followed by neck thickness, equatorial diameter and polar diameter. Highest TSS of 14.5% was recorded in IC573752 (dark red, thick flat, Lohandiguda, Bastar). The thinnest neck (0.18 cm) was found in IC573779 (dark red, ovate) from Bastar, Chhattisgarh. Twenty-five accessions were observed with single centres including IC573729 (light red, ovate, Bastar), IC573743, IC573769 (dark red, globe, Bastar), IC573780 (light red, flat globe, Bastar), IC573794 (white, ovate, Gadchiroli) and IC573810 (white, thick flat, Chandrapur). Largest bulbs were observed in IC573822 (105 g) and IC573820 (97 g) both light red and thick flat, from Yavatmal and IC573774 (94.5 g, light red, globe) and IC573781 (93.5 g, dark red, flat globe) from Bastar. These accessions hold potential for utilization in breeding programmes for further genetic improvement of onion. Specific diversity rich areas identified can be developed into onion villages for on-farm in-situ conservation.