No abstract

The present investigation was carried out at the Agricultural Research Station, Faculty of Agriculture, Alexandria University to evaluate seven faba bean varieties (four local and three introduced) in the diallele cross set. Twenty one crosses were constituted in the winter season of 2006/2007, whereas parents and crosses were evaluated in a yield trial, in winter season of 2007/2008, in a randomized complete block design of three replications. Results revealed highly significant variations within parents and F 1 genotypes indicating a wide genetic variability for the studied characters and the possibility of genetic improvement using such genetic pools of faba bean. Several crosses recorded significant positive heterosis percentages relative to mid parent and better parent for seed yield per plant and 100-seed weight ranging from 17.46-84.95%, 22.47-68.49%, 8.53-23.26% and 10.43-18.64% relative to MP and BP for each character, respectively. Both general (GCA) and specific (SCA) combining abilities were significant for all studied characters revealing the important role of both additive and dominant components in the inheritance of the studied characters. Giza Blanca proved to be a good combiner for all studied characters except number of pods per plant and maturity time. Several crosses exhibited significantly positive SCA effects for studied characters especially Giza 716 × ILB 450 and ILB 450 × Giza Blanca which exhibited highly significant and positive SCA effects for seed yield per plant and 100-seed weight. Heritability in narrow sense was high for 100seed weight (0.54) and short plant height (-0.51) while it was low for seed yield per plant.

Heat tolerance in 45 chickpea, lentil, and faba bean genotypes was investigated during 2007/2008 and 2008/2009 at Alexandria Agriculture Research Station, Alexandria, Egypt, using screening methods employing the membrane thermostability technique. Threshold temperature to be used in screening for heat tolerance at germination was also investigated for each crop. Temperatures, responsible for 50% germination were 40, 33.5, and 29°C for chickpea, faba bean, and lentil, respectively. Germination percent under high temperature varied significantly (P B 0.05) amongst genotypes. Germination percentage ranged from 4.8 to 71.6, 39.2 to 90.0, and 4.8 to 68.6, in chickpea, lentil, and faba bean, respectively. Differences were significant (P B 0.05) among faba bean and chickpea genotypes. Membrane relative injury (RI%) showed significant (P B 0.05) variability among the genotypes and ranged from 10.57 to 58, 5.2 to 61.7, and 15.7 to 52.7 in chickpea, lentil, and faba bean, respectively. Canopy temperature was measured to evaluate heat avoidance in tested genotypes. Infra-red thermometry was used to measure canopy temperature and the gradient of canopy to ambient air temperature (DT C-A ) in moisture stressed and unstressed treatments. Canopy temperature, leaf water potential (LWP) and leaf water content were affected by the level of soil moisture. Genotypes were able to bring their canopy temperatures to levels lower than ambient air temperatures but the differences were not significant. A heat stress index (HSI) were computed relating the DT C-A in moisture stressed to unstressed treatments. Regression of leaf water potential (LWP) and the heat stress index (HSI) was significant (P B 0.05) in faba bean genotypes in the stressful environment. The results of the present investigation emphasize the efficiency of membrane thermostability technique in selection for heat tolerance in early stages of growth in food legumes.

The study aimed at evaluating the effectiveness of pedigree (P), single seed descent (SSD), and mass selection (MS) breeding methods. Two F 2 populations, derived from two crosses, were used. Twenty families derived from each of the three breeding methods in each cross were tested for seed yield (t/ ha), seed yield per plant (g) and its components in F6 generation. A randomized complete block design with three replications was used. Significant differences existed, within F6 families of each cross, for seed yield, seed yield per plant and its components by applying either of the three methods. The widest range in seed yield was obtained by the SSD method. The SSD breeding method produced consistently more superior families in either and over the two crosses with 22, 19 and 18 families for (SSD), (P) and (MS) methods, respectively. The genotypic (δ 2 G) and phenotypic (δ 2 Ph) variances, for seed yield, estimated from SSD method were the highest compared with the other breeding methods over the two crosses. Heritability estimates, in broad sense, and expected genetic advance from selection for higher seed yield indicated that the SSD method recorded higher values (h 2 = 0.87-0.93, δ G = 0.51-0.85) compared with the other two methods. Based on the obtained results, it seems that the SSD breeding method was more effective compared to the other two breeding methods, in producing superior genotypes in seed yield and maintaining genetic variance for further selection and improvement of that character. Considering the partial allogamous nature of the crop, it could be concluded that the SSD method was more efficient and could be less costly in breeding for high seed yield.

The present investigation was carried out at the Agriculture Research Station, Faculty of Agriculture, Alexandria University in the summer seasons of 2005 and 2006, to investigate the influence of three sowing dates (April 10 th , May 1 st and May 20 th) on seed yield and quality characters of six soybean cultivars, i.e.