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

damage, numbers of eggs laid, larval density, number of pods, pods damaged, and grain yield. The overall resistance
score (1 = highly resistant, and 9 = highly susceptible) ranged from 1.5 to 6.0 in the mapping population, 3.0 in
Vijay, 1.3 in ICC 506, and 3.0 in ICCC 37. Percentage pod damage ranged from 5.2 to 29.8% in the mapping
population, 10.5% in Vijay, 7.0% in ICC 506, and 17.4% in ICCC 37. The numbers of larvae at the reproductive
stage were 1.3 to 13.3 in the mapping population, 6.7 in Vijay, 1.3 in ICC 506, and 7.3 in ICCC 37, indicating
considerable variation in the susceptibility of the population and the parents to H. armigera. This population needs
to be genotyped to identify molecular markers for resistance to H. armigera.
HC Sharma and PM Gaur
Milestone: One inter-specific (C. arietinum x C. reticulatum) RIL populations for mapping Helicoverpa resistance
QTLs developed (PMG/HCS) 2009
RILs are being developed from an interspecific cross between ICC 3137 (C. arietinum - susceptible) and IG 72953
(C. reticulatum – resistant). The population was advanced by two generations (F 2 and F 3 ) in the greenhouse during
2006. Some plants died due to root rot disease as the soil used in the greenhouse was infected with the disease. New
crosses were made between these parents and the F 1 s were grown during the off-season in the greenhouse. The F 2
population from the new cross and F 4 progenies from earlier cross are being grown during the 2006/07 cropping
season.
PM Gaur and HC Sharma
Milestone: QTLs for Helicoverpa resistance identified from C. arietinum x C. reticulatum RIL population
(HCS/RKV/PMG) 2010
Newly developed SSR markers at ICRISAT are being screened on the parental genotypes of the mapping population
to identify the polymorphic markers and integrate these into the genetic map.
RK Varshney
Milestone: Characterization of pathotypes of Fusarium oxysporum f. sp. ciceris, Ascochyta rabiei, and Botrytis
cenerea in chickpea and Fusarium udum in pigeonpea (SP) 2009
Characterization of races of Fusarium oxysporum f.sp. ciceris: Chickpea lines identified to be resistant to wilt at
one location often show a susceptible reaction at other locations mainly due to the existence of different
pathotypes/races of the pathogen, F. oxysporum f. sp. ciceris (FOC). Our recent research on races of FOC indicated
that the earlier (early 1980s) race scenario has changed. Hence, we initiated studies to collect races of FOC from
major chickpea growing areas in India. A total of 38 virulent single spore isolates collected from 18 locations in 12
states in India were used for morphological, cultural, and pathogenic characterization of FOC. Of the 38 isolates,
seven were collected from ICRISAT, Patancheru, two from Kurnool (Andhra Pradesh), four from Hisar (Haryana),
one each from Dholi (Bihar), Delhi, Dhaulakuan (Himachal Pradesh), and Gulbarga (Karnataka), two from
Junagadh (Gujarat), one from Sehore, four from Jabalpur (Madhya Pradesh), one from Akola, two from Badnapur,
two from Rahuri (Maharashtra), two from Ludhiana, one from Gurdaspur (Punjab), three from Kanpur, one from
Ghaziabad (Uttar Pradesh), and two from Pantnagar (Uttaranchal) (all in India). Four races, which were reported
during 1982 from India were also included in this study.
Morphological variation: Five mm discs of actively growing five-day old culture of each isolate were transferred
separately onto potato dextrose agar (PDA) medium in 90 mm plastic plates and incubated at 25 0 C for 7 days. Data
on colony color, colony type, zonation, and colony growth (total growth and growth per day) were recorded at 7days
after incubation. Based on type of mycelium, color, and colony growth; all the isolates were categorized into nine
groups: FOCs 4, 8, 10, 16, 27, 32, 37, 38, and R4. Most of the isolates had cottony type of mycelium with erumpent
growth. Isolate FOC 8 had submerged type of mycelium, FOC 16 showed effused growth, and isolate R4 had a
pinkish mycelium.
Cultural variation: The nine isolates, which differed in apparent morphological characters, were used to study
cultural characters. All the nine isolates were multiplied separately on potato dextrose broth medium and incubated
at 25 0 C for 7 days. Data on percent micro and macro conidia, conidial size, and number of cells in macro conidium
were recorded at 7 days after incubation. Considerable variation existed among the isolates in all the parameters
202