In:
Frontiers in Genetics, Frontiers Media SA, Vol. 13 ( 2022-4-12)
Abstract:
The gram pod borer Helicoverpa armigera is a major constraint to chickpea ( Cicer arietinum L.) production worldwide, reducing crop yield by up to 90%. The constraint is difficult to overcome as chickpea germplasm including wild species either lacks pod borer resistance or if possessing resistance is cross-incompatible. This study describes conversion of elite but pod borer-susceptible commercial chickpea cultivars into resistant cultivars through introgression of cry1Ac using marker-assisted backcross breeding. The chickpea cultivars (PBG7 and L552) were crossed with pod borer-resistant transgenic lines (BS 100B and BS 100E) carrying cry1Ac that led to the development of BC 1 F 1 , BC 1 F 2 , BC 1 F 3 , BC 2 F 1 , BC 2 F 2 , and BC 2 F 3 populations from three cross combinations. The foreground selection revealed that 35.38% BC 1 F 1 and 8.4% BC 1 F 2 plants obtained from Cross A (PBG7 × BS 100B), 50% BC 1 F 1 and 76.5% BC 1 F 2 plants from Cross B (L552 × BS 100E), and 12.05% BC 2 F 2 and 82.81% (average) BC 2 F 3 plants derived from Cross C (PBG7 × BS 100E) carried the cry1Ac gene. The bioassay of backcross populations for toxicity to H . armigera displayed up to 100% larval mortality. BC 1 F 1 and BC 1 F 2 populations derived from Cross B and BC 2 F 3 population from Cross C segregated in the Mendelian ratio for cry1Ac confirmed inheritance of a single copy of transgene, whereas BC 1 F 1 and BC 1 F 2 populations obtained from Cross A and BC 2 F 2 population from Cross C exhibited distorted segregation ratios. BC 1 F 1 plants of Cross A and Cross B accumulated Cry1Ac protein ranging from 11.03 to 11.71 µgg −1 in leaf tissue. Cry1Ac-positive BC 2 F 2 plants from Cross C demonstrated high recurrent parent genome recovery (91.3%) through background selection using SSR markers and phenome recovery of 90.94%, amongst these 30% plants, were homozygous for transgene. The performance of BC 2 F 3 progenies derived from homozygous plants was similar to that of the recurrent parent for main agronomic traits, such as number of pods and seed yield per plant. These progenies are a valuable source for H . armigera resistance in chickpea breeding programs.
Type of Medium:
Online Resource
ISSN:
1664-8021
DOI:
10.3389/fgene.2022.847647
DOI:
10.3389/fgene.2022.847647.s001
Language:
Unknown
Publisher:
Frontiers Media SA
Publication Date:
2022
detail.hit.zdb_id:
2606823-0
