line x 3 tester mating design along with 5 rice genotypes and 6 F1s were used of line, tester was higher than that of interaction of line x tester for all the characters. The predictability ratio indicated the predominance of non-additive gene action in the inheritance of all these characters. The highest significant heterosis (61.9) was observed in the cross Super Basmati/DM-107-4 for yield/plant. The female Super Basmati, male DM-25 and DM-107-4 were observed to be good general combiners for most of the characters studied. The crosses between Basmati-370/DM-25 and Super Basmati/DM-107-4 were observed good specific combiners for yield/plant. However, the cross combination Basmati-370/EL.-30-2-1 was identified as the promising specific combiner for further improvement in rice.

Line x tester analysis in basmati rice

Two hundred and forty nine chickpea mutants in M4 generation developed through gamma irradiation and Ethyl methane sulphonate (EMS) were screened along with their respective parents and susceptible check Aug-424 for resistance to Fusarium wilt in natural wilt sick plot during 2003-2004 seasons. All the 4 parent genotypes showed highly susceptible reaction to Fusarium wilt. Out of a total of 249 morphological mutants of 4 genotypes, 75 mutants exhibited highly resistant reaction (less than 10 %) followed by 31 mutants resistant (11 to 20%), 34 mutants moderately resistant / tolerant (21 to 30%), 35 mutants susceptible (31 to 50%) and 75 mutants were highly susceptible (50 to 100%). The mutagenic treatments proved to be effective in producing morphological mutations along with improved tolerance to Fusarium wilt. These mutants with resistant to tolerant reaction for Fusarium wilt could be used in hybridization program for transferring of resistance genes into high yielding elite cultivars/ producing better recombinants.

Screening of chickpea (Cicer arietinum) induced mutants against Fusarium wilt.

Air dried seeds of local variety Punjab-1 were treated with 0.2% and 0.3% solution of ethylmethane sulphonate (EMS) and planted in the field during Rabi 1996-97 to raise M1 generation. The subsequent generations were raised alongwith parents and standard check varieties
from 1996 to 2000 and selections were made on the basis of high yielding, bold seeded and wilt resistance. The wilt resistance was checked and confirmed by growing the mutants in natural wilt sick plot. During 2000-01, twelve mutants were evaluated in the yield nursery and eight high
yielding mutants were selected. The potential of the mutant line CM94/99 alongwith parent (Pb-1) and check variety (CM2000) was evaluated for yield and adaptation in station and multilocational yield trials conducted from 2001-02 to 2007-2008. CM2008 is a high yielding variety (30% higher yield than check CM2000 and 34% higher
yield than Pb-1). The major improvement in CM2008 is manifested in the form of increase in the seed size. The bold seed size (24.0 g) as compared to parent variety Pb-1 (16.5 g) was the main contributing factor towards increase in seed yield. It is resistant to Fusarium wilt and tolerant to Ascochyta blight. Its average yield is 1800 kg/ha and yield potential is 3000 kg/ha. Punjab Seed
Council approved CM94/99 variety as a commercial variety under the name of "CM2008" for general cultivation in Punjab. This resistant variety will greatly help to stabilize the chickpea production in the country.

High yielding kabuli mutant chickpea (cicer arietinum l.) variety "cm 2008"

Deviations observed by Metroglyph method regarding the number of clusters formed, number of genotypes in each cluster and superimposition of the genotypes within the cluster pointed out the precision and refinement of the technique in studying the germplasm collection. It is noted that through induced mutation genetic improvement for yield and yield components is possible. Metroglyph scatter diagram provided the possibility of 11 clusters of rice genotypes. Cluster-I and cluster-II possessed the highest index scores i.e., 66 and 56 respectively on morphological basis. On the basis of this clustering, it can be interpreted that mutants between cluster-I and cluster-II is expected to give better types after hybridization.

M.A. Awan

Papers

Mutation breeding for crop improvement: a review