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

Activity A6.2: Develop and evaluate diverse groundnut breeding populations, lines and varieties while
developing the capacity to screen for GRD, foliar disease resistances and aflatoxin contamination in the
NARS
Milestone A6.2.1: Infector row technique for screening of GRD resistance established and operational with at least
one NARS in ESA by 2008 (ESM)
2006 - Targeted milestones:
• Diverse populations of groundnut developed through conventional and marker assisted selections
• Local germplasm deployed in the breeding program for incorporating specified traits (e.g. adaptation, yield
grain type and disease resistance)
Diverse breeding populations, lines and varieties and capacity to screen for GRD and foliar diseases (rosette,
ELS, LLS, and rust). The infector row technique is currently in use at the ICRISAT Chitedze Research Centre with
Malawi NARS.
The rosette disease pressure was excellent. There was 100% infection in the spreader rows and susceptible checks.
The observed resistant progeny selections above were therefore a true reflection of genetic resistance in the selected
progenies.
From 16 nurseries ranging from F4 – F6 in 1003 progeny rows, a total of 636 plants were identified for generation
advance through single plant selection. Out of these we identified 58 single plant selections from 8 of the nurseries
with 0% rosette incidence (9% of total) and an additional 66 plants with rosette incidence ranging 1 - ≤ 20%.
From seven F7 nurseries with 468 progeny rows, a total of 323 were selected for promotion to checkrow trials, out
of which 91 had 0% rosette incidence.
Most of the inter-specific derivative progenies exhibited susceptible reaction to ELS. Even the 13 selected single
plants had relatively higher ELS than many of the selections from other nurseries. This finding has implication on
the nature of resistance and inheritance of ELS from wild Arachis that may need further investigation.
There are excellent progenies both in Check row trials and in F7 that combines ELS and rosette resistance. As seen
in the table above, our efforts of pyramiding these two constraints are starting to pay off.
Good progress has been made in identification of ELS resistant progenies received from ICRISAT-Patancheru.
From an initial nursery of 443 F2 planted in 2004, we have identified 80 progenies with very good levels of
resistance to ELS for promotion to F4 families. In pyramiding ELS resistance genes, 240 F5 single plant family
progenies have been selected for generation advance to F6 in ELS x ELS crosses and 48 single plant family
progenies identified in F4 combining ELS resistance with confectionary market traits.
Achievements on single plant selection program for segregating breeding populations in the Rust and LLS nursery:
There were three segregating population nurseries:
• From 104 F6 Rust and LLS Resistance screening nursery, 81 families were identified for generation
advance
• From 1673 F7 Rust and Rosette Resistance nursery a total of 408 families were selected to make two sets
of checkrow trials each comprising 204 entries
• From 216 entries of the checkrow trial, 62 lines were identified to develop Preliminary Rust and LLS Trial
each consisting of 31 entries plus checks (36 entry trials)
The disease pressure for 2006 was low hence most of the selections were based on yield and adaptation to the Low
altitude hot humid environment of the Malawi Lake Shore.
ES Monyo
Lead NARS crop improvement Networks for Groundnut Research in ESA:
Through the McKnight Foundation that funded a project on “Developing short-and medium-duration groundnut
varieties with improved yield performance, acceptable market traits and resistance to foliar diseases”. This project
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