Host Plant Resistance for Bruchids in Pre-breeding Lines of Greengram [Vigna radiata (L.) Wilczek]

Abstract

Background: Bruchid beetle (Callosobruchus chinensis) is one of the devastating field carry over storage pest causing a huge crop loss, especially in greengram. The pre-breeding lines were developed by crossing between a cultivated variety, VBN (Gg) 2 and Vigna radiata var. sublobata, a progenitor species of greengram used as a resistant parent against bruchid. Methods: A total of 53 stabilized inter sub-specific lines along with parents were screened for bruchid resistance by ‘no choice’ method with two replications. Screening parameters were recorded for all the 53 lines and were statistically analysed. Damage assessment was carried out and the three resistant lines obtained during initial screening was further confirmed. Result: The low seed damage per cent was observed in three lines viz., GGISC-2 (18.00), GGISC-21 (20.00) and GGISC-49 (14.00). The susceptibility index was 0.048, 0.049 and 0.048 in GGISC-2, GGISC-21 and GGISC-49, respectively and hence, classified as bruchid resistant. Delayed adult emergence, uneven adult emergence, prolonged developmental period, small and malformed adults were the other parameters observed in resistant lines. The three resistant lines identified could be further utilized in the breeding programmes for the development of bruchid resistant varieties in greengram.

Host Plant Resistance and Analysis of Chemical Compounds Responsible for Bruchid Resistance in Greengram Vigna radiata (L.) Wilczek

“…The three resistant lines recorded less weight loss per cent of seed viz., 11.59 per cent (GGISC 124), 12.41 per cent (GGISC 140) and 11.37 per cent (GGISC 150), whereas susceptible check [VBN (Gg) 2] recorded the highest seed weight loss of 59.15 per cent (Table 1). Seram et al (2016) and Harshitha et al (2022) reported less weight loss per cent of seed in bruchid resistant lines of greengram.…”

“…Seed damage per cent on 30 th day was less than twenty per cent in three resistant lines viz., 17.00 per cent (GGISC 124, GGISC 150) and 18.00 per cent (GGISC 140), whereas the susceptible check (VBN (Gg) 2) reached 100 per cent adult emergence on 30 th day of inoculation (Table 1). Harshitha et al (2022) also reported the 100 per cent adult emergence on 30 th day of inoculation in VBN (Gg) 2. Sarkar and Bhattacharyya (2015) and Soumia et al (2017) reported that in susceptible varieties of greengram, the susceptibility index was more than 0.050 and the seed damage was more than 40 per cent.…”

“…The three resistant lines recorded susceptibility index less than 0.050 (resistant category) viz., 0.046 (GGISC 124), 0.047 (GGISC 140) and 0.048 (GGISC 150), whereas the susceptible check [VBN (Gg) 2] recorded the susceptibility index of 0.085 (Table 1). Neupane et al (2016), Gosh et al (2020) and Harshitha et al (2022) have also used the susceptibility index and weight loss per cent for determining the level of bruchid resistance in greengram and were found to be high in susceptible lines.…”