JWSS - Journal of Water and Soil Science

---

Flax (Linum usitatissimum L.) is an oilseed and widely adapted crop. Oil of regular genotypes of flax is used in industry because of its unique fatty acid profile. New, mutant genotypes of flax have oils similar to sunflower oil which can be used as edible oil. This experiment was conducted to investigate the genetic variation of agronomic traits and productivity in different edible and industrial oil genotypes of flax in Isfahan. The genotypes were evaluated in augmented design.

Based on the results, the average numbers of seedling/m² in edible and industrial oil genotypes were 178 and 367 with variation coefficients of 70 and 10%, respectively. Maturity also showed variation and varied between 89 to 116 days in edible oil genotypes and between 89 to 128 days in industrial oil genotypes. Plant height varied between 57 to 86 and 49 to 73 cm in edible and industrial oil genotypes, respectively. Seed yield also had considerable variations and varied between 429 to 2651 and 779 to 2389 kg/ha with variation coefficients of 35 and 25 in edible and industrial oil genotypes, respectively. Seed yield per plant showed a high and positive correlation with basal branches (r=0.77**) and bolls per plant (r=0.93**), but high and negative correlation with stand (r=-0.66**). Regression analysis revealed that approximately 96% of the variation in seed yield per plant was attributed to variation in bolls per plant, seeds per boll and seed weight and they were determined as the major yield components, respectively. Bolls per plant was the most important yield component and contributed to 87% of the variation for seed yield per plant.

---

To estimate the relationship between honey yield and some of the morphological characters, five queen-daughters from each of 30 queen-mothers were studied. The queen-mothers were selected randomly from the apiary of Research Center of Animal Science and Natural Resources in Isfahan Province. Summer honey yield was measured from the difference of honey comb before and after honey extraction while fall honey production was calculated from area of sealed honey combs. Morphological characters were recorded using a stereodissecting microscope fitted with a calibrated micrometer reticule according to Ruttner’s procedures. The mean of honey yield for a year was estimated to be 10.05 kg. Phenotypic correlations between yearly honey production and summer and fall honey productions were estimated to be 0.49 and 0.88, respectively, while the correlation between summer and fall honey yields was low (0.019). There were significant correlations between summer honey yield with cubital-b index, tibia length and forewing width (0.28, 0.27 and 0.25, respectively). Also there were significant correlations between metatarus width with total and fall honey yields (0.22 and 0.23, respectively). Genetic correlations between metatarus length and cubital index with summer honey yield were negative (-0.75 and -0.45, respectively). It may be concluded that due to the high correlation between summer honey production and total honey yield, one could improve yearly honey production by selecting on the basis of summer yield of colonies. Among morphological traits, metatarus length, forewing width and cubital index could be used in the breeding plan in order to increase honey yield.

---

Information about nonexchangeable potassium (NEK) release rate in Hamadan soils is limited. The objective of this study included an investigation of the dynamics of NEK in some soils from Hamadan Province by successive extraction with dilute citric acid over a period of 2500 h and determination of the correlation between the rate constants in this kinetic equation with soil properties. The results of this experiment showed that the initial NEK release rate was rapid which slowed down later on. The amount of NEK released after 2500 h ranged from 0.87 to 2.89 cmol kg^-1. The amount of NEK released after 2500 h was significantly correlated with CEC, NEK, and soil separates. First order, parabolic diffusion law and power function equations described well the NEK release kinetics based on their highest determination coefficient and their lowest value of the standard error of the estimate. Release rate constant in the first order, parabolic diffusion law and power function equations ranged from 1.0×10^-4 to 3.0×10^-4, 1.7×10^-4 to 10.6×10^-4 and 2.75×10^-1 to 4.6×10^-1, respectively. In the correlation study the rate constants in the kinetic equations were correlated with some chemical properties and particle size distribution. The results of this experiment also showed that dilute citric acid can be used in the study of NEK release.

---

To evaluate heritability, phenotypic and genotypic correlation coefficients, phenotypic and genotypic variances as well as relationships between some of the grain quality traits, an investigation was conducted in a randomized complete block design replicated three times in 2001, using four durum wheat genotypes PI40100, Dipper-6, Oste/Gata, Shova and their F₂ and F₃ progenies derived from their crosses. Grain quality characteristics including seed hardiness, protein content, SDS sedimentation volume and gluten content were evaluated. The results indicated that wet gluten content and dry gluten content had the highest coefficient of variation. Statistical analysis showed a significant difference between genotypes for all traits with the exception of SDS sedimentation volume. Dry gluten content had the highest heritability (90.4%) while SDS sedimentation volume had the lowest heritability (48.6%). Results of correlation analysis indicated that seed hardiness correlated significantly with protein content, SDS sedimentation and dry gluten content. Protein content had a positive correlation with wet and dry gluten content. Since dry gluten content showed a high correlation with protein content (quantity) and seed hardiness had a high correlation with SDS sedimentation volume, hence these two traits can be used as the selection criteria for improving quality of protein in durum wheat.

---

In this study external fat-tail dimensions (upper, middle and lower width, length, length of gap, depth and upper circumference) and fat-tail weights collected on 724 Lori-Bakhtiari sheep were used to study external fat-tail dimensions and their relationships with fat-tail weights. Sheep were 3 months to 6 years old and slaughtered at the industrial slaughter house of Joneghan in Chaharmohal and Bakhtiari province in 2003. The mean of fat-tail dimensions were estimated as 15.83, 23.85, 24.73, 26.52, 14.96, 14.12 and 52.59 cm for upper width, middle width, lower width, length, length of gap, depth and upper circumference, respectively. Fat-tail weight varied from 0.10 to 20.60 with overall mean of 2.71 kg. Fat-tail percentage varied from 1.18 to 37.18 with overall mean of 11.87 percent. The effects of fixed factors of age, sex and body condition of sheep on all of traits were highly significant (p<0.0001). The least square means of all traits except fat-tail percentage were increased with increasing age of sheep. Lowest least square mean (± s.e) of 2.12 ± 0.25 kg fat-tail weight and 7.91 ± 0.72% fat-tail were observed for sheep having body condition score of 1 and the highest least square mean with fat-tail weight of 9.84 ± 0.56 kg and fat-tail percentage of 20.59 ± 1.63 were observed for sheep having body condition score of 5. Estimation of correlation coefficients among external fat-tail dimensions and fat-tail weight were positive and varied from 0.60 between upper fat-tail width and fat-tail weight to 0.83 between upper circomference of fat-tail and fat-tail weight. Upper circumference of fat-tail accounted for %69.5 of variation of fat-tail weight. This study showed that fat-tail weight in live sheep of Lori-Bakhtiari could be estimated using external fat-tail dimensions with very high accuracy (r = 0.904).