Stability of Cytoplasmic Genetic Male Sterility and Fertility Restoration in Pigeonpea

Abstract

In cytoplasmic genetic male sterility-based (CGMS) hybrid seed
 production, instability of expression of male-sterility and fertility
 restoration across a wide range of environments are two of the
 major difficulties. Therefore, the present study was carried out to
 investigate the stability of male sterility of nine CGMS lines under
 three dates of sowing and the fertility restoration of 10 CGMS-based
 pigeonpea ( Cajanus cajan (L.) Millsp.) hybrids at three different
 locations. Significant variability existed for pollen fertility among
 hybrids and sterility among cytoplasmic male sterile (CMS) lines.
 All the hybrids except ICPH 3494 and ICPH 3491 exhibited high
 (>80%) pollen fertility across locations. Hybrids ICPH 2671, ICPH
 2740, and ICPH 3933 had 100% male-fertile plants across locations.
 All the CMS lines had completely male-sterile plants across
 sowing dates. The CMS lines BRG1 A, Hy3C A, BRG3 A, and TTB7 A
 exhibited 100% pollen sterility at different sowing dates. The pooled
 analysis revealed a significant genotype × environment interaction
 for pollen fertility and sterility. The genotypic main effect
 + GE (GGE) biplot of hybrids showed that hybrids ICPH 2671,
 2740, 3933, and 3461 were stable for fertility restoration. With the
 exception of ICPA 2047 and ICPA 2051, all the CMS lines were
 highly stable with high mean performance and least distance from
 AEA (average environmental axis). Male-sterility in A4 cytoplasm
 was independent of environmental conditions. Different dates of
 sowing did not affect expression of male sterility of these CMS lines