ICRISAT Archival Report 2006 - The seedlings of success in the ...

Milestone 5A.4.1.2: A hybrid seed production manual published (KBS, 2006)
To guide scientists and seed producers involved in hybrid pigeonpea research and development a manual entitled
“Hybrid Pigeonpea Seed Production Manual” was published in 2006. This manual contains the detailed information
on various aspects of seed production technology of pigeonpea hybrids and their parents.
KB Saxena
Output Target 5A.5: Efficiency of hybrid pigeonpea breeding improved through strategic research (2010)
Activity 5A.5.1: Conduct strategic research to improve the efficiency of hybrid breeding
Milestone 5A.5.1.1: Cytology and genetics of A 4 CMS system and its fertility restorers investigated (VD/KBS, 2007)
Transverse sections of young anthers from male-sterile and fertile plants showed no differences in the development
of sporogenous tissues. The process of microsporogenesis was similar in both up to differentiation of PMCs into
tetrad formation and differed thereafter. The PMCs of the male-sterile plants became shriveled due to breakdown of
the tapetum layer, which not only gives support but also provides nutrition to PMCs. In the case of fertile plants, the
process of microsporogenesis proceeded normally and all the layers of anther wall had developed by the time PMCs
had formed. Unlike the male-sterile plants, the tapetum layer in the fertile plants was also found to be persistent till
the development of pollen grains and subsequently ruptured to release the pollen grains.
Vijay Dalvi and KB Saxena
Milestone 5A.5.1.2: Genotype - environment interaction for the expression of male-sterility and fertility restoration
assessed (KBS/VD/KML, 2009)
Stability of CMS lines: For commercial production of high-yielding hybrids, it is essential to identify stable CMS
lines. Three CMS lines with diverse cytoplasm were selected for this study. These include ICPA 2067 (A 1
cytoplasm), ICPA 2052 (A 2 cytoplasm), and ICPA 2039 (A 4 cytoplasm). These lines were evaluated at Parbhani and
Patancheru during 2004 and 2005 rainy seasons. The observations on pollen staining showed that ICPA 2039 was
the most stable CMS line at both locations. In case of ICPA 2052, five out of 49 plants showed fertile pollen grains
(5−30%) and the remaining plants were male-sterile at Patancheru. More or less similar results were observed at
Parbhani. ICPA 2067 was found to be the most sensitive to the environmental changes, as 24 out of 28 male-sterile
plants, reverted to male-fertility in winter months at Patancheru. At Parbhani also, 24 out of 36 male-sterile plants
reverted to male-fertility.
Stability of fertility restoration: In general, the testers performed differently with regards to the fertility restoration
of the three CMS lines. At Latur (18 o N), three testers (ICPL 129-3, BWR 23, and Nirmal 2) restored the male
fertility of CMS line ICPA 2067, while BSMR 175 showed only 35% fertility restoration. The testers BDN 2,
BSMR 736, and BSMR 853 showed >70% fertility restoration with ICPA 2067. These three testers can be purified
to get 100% fertility restoration with ICPA 2067. Out of seven F 1 hybrids developed on ICPA 2052, three testers
(ICPL 129-3, Nirmal 2, and BSMR 175) maintained complete male-sterility and four testers (BDN 2, BWR 23,
BSMR 736, and BSMR 853) showed partial (60–80%) fertility restoration. The F 1 hybrids developed on ICPA 2039
showed that only ICPL 129-3 maintained complete male-sterility, while BSMR 736 restored complete fertility. The
other five testers segregated for fertility restoration (66–85%). These testers can be purified to get 100% fertility
restoration for development of hybrids. The results of the present study revealed that although there were
differences among testers for fertility restoration of different cytoplasm, the genotype × environment interactions
were not strong enough to influence selection and breeding of hybrids.
KB Saxena, Vijay Dalvi and K Madhavi Latha
Milestone 5A.5.1.3: New sources of cytoplasm identified and diverse CMS systems developed (KBS/NM/KML,
2010)
Crosses between diverse pigeonpea cultivars and wild species Cajanus acutifolius gave rise to F 1 hybrids. It was
consistently observed that hybrids between pigeonpea cultivar ICPL 85010 and C. acutifolius ICCW 15613 gave
rise to hybrids with high degree of male sterility. These hybrids were crossed with diverse pigeonpea cultivars to
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