Eight genotypes of Saccharum officinarum were crossed with Saccharum spontaneum and 14 genotypes of S. officinarum were crossed with Erianthus arundinaceus. A total of 39 hybrids were evolved. These 39 hybrids were raised in the field and used as donor clones for in vitro culture studies. Plantlets were regenerated from 1-month-old callus. The grown up plants were transplanted to well prepared field, to study the variations generated for the biometric as well as for biochemical characters. There were significant differences between the donor clones and their sub clones for all the character of interest. The somatic segregation was gradual and wider, showing a range of divergence from the mean towards the end of the scale. Fifty-one sub clones were selected with commercial potential which have 13% fibre, 200 cm stalk length, 10 cm internode length and pure obtainable cane sugar per cent of 10.

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Three parents with three different durations were crossed in full diallel fashion. The resultant six hybrids were selfed along with their three parents to get six F 2 's. The F 2 's were selfed to obtain six F 3 's. The aforementioned five generations of the six crosses were studied for days to flowering, number of productive tillers per plant, number of filled grains per panicle, 100 seed weight, grain L/B ratio, grain yield per plant and harvest index. The distribution pattern of the segregating generations revealed that, the F 3 's of the cross ADT 38 x ADT 37 for hundred seed weight and the F 3 's the cross ADT 38 x ADT 44 for grain yield per plant showed normal symmetrical distribution. The kurtosis value was almost negligible indicating mesocurtic nature of the distribution. The F 3 's of ADT 38 x ADT 44 recorded high mean coupled with higher coefficient of variation, indicating the presence of additive genetic control. The higher mean performance in F 3 may be due to accumulation of favourable genes. All the other crosses and generations showed asymmetric distribution in positive as well as negative direction, for almost all the characters of interest. The mean was comparatively higher but the coefficients of variation were comparatively lower, indicating the preponderance of non-additive genetic control in the expression of the traits of interest. It is better to resort to intermating of segregants followed by recurrent selection for further improvement. The F 3 's unique cross ADT 38 x ADT 44 had taken less number of days to first flowering, higher grain L/B ratio coupled with higher grain yield. A simple selection among the F 3 progenies of the cross ADT 38 x ADT 44 may yield some useful segregants with earliness, desirable grain quality and higher grain yield.

Seventy genotypes of rice were evaluated under three seasons. Additive main effects and multiplicative interaction (AMMI) model was applied to ascertain extent of genotype ´ into season interaction (GSI) and also the stability of rice genotypes over three seasons. Significant difference was observed by AMMI analysis among the 70 genotypes as well as seasons. The sum of the first principal component accounted to 87.04% of the GSI. In the present inquiry, the genotypes viz., G26 (484.45 mg), G17 (474.78 mg) and G31 (377.87 mg) registered with high mean per day productivity and coupled with higher PCA scores. The aforementioned genotypes are exclusively suitable for favourable seasons. The genotypes G7 and G11, were nearer to the center point axes. They were influenced with the seasons. These genotypes had maximum per day productivity as well as stability and hence suitable for different seasons.

Six × six full diallel mating involving six parents viz., (P1) ADT 37, (P2) ADT 43, (P3) ADT 45, (P4) ASD 16, (P5) CO51 and (P6) CO47 was effected to evolve 30 hybrids in rice crop. The six parents along with their 30 F 1 hybrids were evaluated for ten agronomic traits viz days to 50 per cent flowering, plant height at maturity, the number of productive tillers per plant, panicle length, the number of filled seeds per panicle, seed length, seed breadth, seed L/B ratio, hundred seed weight and seed yield per plant. The traits viz., seed length and seed L/B ratio were controlled by complete dominance. Incomplete dominance was found to operating in the expression of the traits viz., the number of filled seeds per panicle and seed yield per plant. Partial dominance can be had as semi additivity. On the other hand, the traits viz., days to 50 per cent flowering, plant height at maturity, panicle length, seed breadth and hundred seed weight were controlled by over dominance. Apart from this amphi directional dominance was well evidenced from the correlation coefficient of Yr and Wr -Vr as well as Vr -Wr graph. It is earnestly advised to inter-cross among the parents to evolve high heterotic lines and/or improved populations.