الفهرس 
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Abstract
The experiments were carried out during the two growing seasons of 2020-2021 and 2021-2022 applying three different irrigation systems i.e. drip, sprinkler and surface irrigations for 20 genotypes of faba bean differed genetically. Both of drip and sprinkler irrigation were practiced across the sandy lands at El-Arshadiaa farm in El-Ghorib Experimental farm, as well as the surface irrigation conducted at clay lands at Agronomy Experimental farm of Agronomy Dept., Faculty of Agriculture, Assiut University. The Randomize Complete Block Design (RCBD) in three replications was used for all experiments. Each genotype grown in one ridge 3m long, 60 cm apart and 30 cm between plants within ridge with two plants in the hole in both sides of the ridge.
The total irrigated water for each system was used as 1500 m3 in equal amount of water across different irrigation times according the irrigation system during the season. The number of irrigation times were four for surface, and fifteen for both of drip and sprinkler systems during the sowing season, respectively.
The results of the present investigation could be summarized as:
- The results illustrated significant differences among studied faba bean genotypes and their different response correlated with the changed irrigation system and how they genetic make-up reacted with these conditions for the studied traits. Furthermore, the insignificant and significant mean square for some traits in few cases from season to another under same or different irrigation system indicating that the different effects of these condition on the performance for those traits and genetically different reacted response of the genotypes and be unstable from season to season either under these conditions.
- Over the two seasons, the drip irrigation reduced the heritability coupled with GCV and PCV for seven traits i.e. plant height, no. of branches/plant, no. of pods/plant, weight of pods/plant, seed yield/plant, seed yield/plot and threshing percentage in values of -27.66 and -28.96, -21.84 and -7.54, -21.34 and -20.71, -5.61 and -0.56, -15.68 and -15.32, -1.81 and -0.02, and -69.52 and -81.90% for heritability comparing to surface and sprinkler irrigations, respectively. It is clear conclusion that all these seven traits were correlated to the seed yield productivity which exerted as the maximum genetic make-up of the studied faba bean genotypes using the optimum water use efficiency and furnished favorable conditions to drip irrigation. Consequently, less differences among these faba bean genotypes which may be reduced the estimates of heritability, GCV and PCV for the previous traits under drip irrigation. Meanwhile, sprinkler reduced heritability coupled with GCV and PCV for four traits i.e. seed index, weight of pods/plot, days to first and 50% flowering in values of -5.35 and -374, -3.63 and -8.75, -13.27 and 20.81, and -20.77 and -10.16% for heritability comparing to drip and surface irrigations, respectively. The surface irrigation system reduced the heritability coupled with GCV and PCV for only two traits i.e. length of first pod and chlorophyll content in value of -3.33 and -5.16, and -24.68 and -28.55% for heritability comparing to drip and sprinkler irrigation, respectively.
- The drip irrigation increased the values of heritability, GCV and PCV for only two traits i.e. seed index and days to 50% flowering in values of 1.70 and 5.66 and 13.40 and 26.22% for heritability comparing to surface and sprinkler irrigations, respectively. Moreover, surface irrigation increased heritability, GCV and PCV for seven traits i.e. no. of branches/plant, no. of pods/plant, weight of pods/plant, seed yield/plant, seed yield/plot, weight of pods/plot and days to first flower in values of 27.94 and 18.29, 27.12 and 0.80, 5.94 and 5.36, 18.60 and 0.42, 1.84 and 1.82, 5.61 and 9.59, and 9.52 and 26.28% for heritability comparing to drip and sprinkler irrigations, respectively. In same context, sprinkler increased heritability coupled with GCV and PCV for four traits i.e. plant height, length of first pod, threshing percentage and chlorophyll content in values of 40.77 and 1.83, 1.93 and 5.44, 452.49 and 68.40, and 5.41 and 39.95% for heritability comparing to drip and surface irrigations, respectively.
- The seed yield and its main attributes were very impressed with the challenged environment conditions from season to another under different system of irrigation which expressed to the different response of the genetic make-up in view of different values of heritability, GCV and PCV.
- It is remarkable result for ranking the superiority of irrigation systems for the genetic performance resulted from the current faba bean genotypes over the two seasons, the drip pointed the first onto eleven out of thirteen studied traits. This superiority of drip irrigation was divided into two groups i.e. (a) the drip followed by surface and then sprinkler irrigations for eight traits i.e. plant height, length of first pod, no. of branches/plant, no. of pods/plant, weight of pods/plant, seed yield/plant, seed yield/plot and weight of pods/plot, and (b) the drip was in the first followed by sprinkler and then surface irrigations for three traits i.e. seed index, days to first flower and days to 50% flowering. Otherwise, the drip irrigation became the third one only for the remaining two traits i.e. threshing percentage and chlorophyll content.
- Concerning to the average of all traits for separate faba bean genotypes under all environments (two seasons and three irrigation systems), the genotypes nos.15 and 17 were superior and possessed the highest estimates for seed yield and its main attributes especially under drip and surface irrigations. It was remarkable result that the genotypes no. 17 revealed to be the highest one for no. of pods/plant under the sprinkler irrigation. Moreover, the genotype no.17 recorded the lowest length of first pod (19.47 cm) under drip and be in second order under surface (22.47 cm) and sprinkler (14.87 cm) irrigations with no significant differences comparing with genotype no 15 under surface and sprinkler irrigations Consequently, both of genotypes no. 15 (Sahara) and 17 (Dwarf) exhibited to be in high place for their superiority comparing to the rest genotypes for seed yield and its main attributes.
- In general focus, the powerful positive and highly significant values of correlation coefficients which mostly closed to unity under all irrigation systems i.e. drip, surface and sprinkler in both seasons were exerted between weight of pods/plant and seed yield /plant; seed yield/plot and weight of pods/plot; days to first flower and days to 50% flowering. Moreover, weight of pods/plant and each of seed yield/plot and weight of pods/plot; seed yield/plant and each seed yield/plot and weight of pods/plot under drip irrigation in second season and surface and sprinkler irrigations in both seasons. The same trend could be found between number of pods/plant and each of weight of pods/plant and seed yield/plant under drip and surface irrigation systems in both seasons. This finding of correlation values among seed yield and its main components revealed that the both drip and surface irrigation systems save enough water use efficiency to be produced may be maximum genetic make-up for photosynthesis and accumulation products in seeds of faba bean. Furthermore, the monitor of correlation values between most studied traits exerted the exhausted environment role in the expression of the genes, thereby establishing various inherent relationship among the studied traits of faba bean. These results of stable relationships among seed yield, number and weight of pods per plant or plot under all irrigation systems (drip, surface and sprinkler) in both seasons accounted to be indicators for net seed yield of faba bean, hence could be selected individually or simultaneously for increase and improvement yielding ability through breeding programs of faba bean.
- The path-analysis in type I revealed that the no. of pods/plant exhibited the highest positive direct effect on seed yield/plant under drip (0.8181 and 0.4895) and surface (0.5248 and 0.4805) through the first and second seasons, respectively. The path analysis type II revealed that the main positive direct effects, which mostly close to unity, on seed yield/plant were resulted from the weight of pods/plant and recorded 1.0361 and 0.9485 under drip, 0.3656 and 1.0179 under surface, and 0.7715 and 0.9424 under sprinkler in first and second seasons, respectively. The positive and high direct effect of no. of pods/plant (0.8937) on seed yield/plant was recorded under surface irrigation in first season. It is remarkable result that the residual effects in type II were decreased rapidly compared to type I of path-analysis. This due to the very high positive both direct and indirect effects for weight of pods/plant on seed yield/plant.
- The drip irrigation was the largest one in value of 1.24 kg/m3 for the efficiency of water productivity for seed yield/fed. The surface irrigation ranked in the second order which possessed 1.23 kg/m3 and accounted 99.19% comparing to the drip irrigation. Otherwise, the sprinkler irrigation was the poorest one which produced water productivity only 0.82 kg/m3 and accounted 66.13 and 66.67% comparing to the drip and surface irrigation systems, respectively.
- Two common methods used for multi-environment experiments, i.e., the additive main effects and multiplicative interaction (AMMI), and genotype plus genotype environment interaction (GGE) biplot. The ANOVA for AMMI model revealed highly significant differences among tested genotypes, investigated environments (irrigation systems), and genotype-by-environment interaction (GEI) for measured traits except thrashing percentage that showed insignificant GEI. Moreover, partitioning the GEI by AMMI analysis revealed that the first two terms of AMMI (IPCA1 and IPCA2; Interaction Principal Components Axis term 1 to 2, respectively) were significant for all studied traits except thrashing percentage, which IPCA2 was non-significant. Interestingly, the effect of environments (E) and GEI are more than four and three times the effect of genotypes (G) in seed yield trait, respectively. The GGE biplot analysis revealed negative correlations among each pair of environments in most cases, especially sprinkler irrigations (Spr-1 and Spr-2) showed long vectors from the origin. For seed yield, most of the high yielding genotypes were adapted to drip and surface irrigation environments which had mean performance above the average. Based on this, drip irrigation system comes first, then surface irrigation and last sprinkler irrigation. The genotypes G06, G08, G10, G13, G16, G18, and G20 could be considered as high yielding and stable genotypes across environments, G15 was the superior one but had great variability (unstable).
- The results revealed a wide genetic variability among different faba bean genotypes. The high level of polymorphism indicates the genetic divergence among the studied genotypes, suggesting that ISSR marker was ideal for the study of the genetic diversity among closely related genotypes. The results indicated the presence of a considerable genetic variability among tested faba bean genotypes. The ISSR primers ISSR markers are a valuable tool for detecting genetic diversity among faba bean genotypes and for varietal identification and fingerprinting due to the presence of adequate numbers of varietal specific bands. Hence, reliance on molecular variability assessment would be a better option for the faba bean breeder.