Estimation of variability and estimation of genetic variance component¡ heritability of fruit's characteristics and combining ability of Pistacia atlantica in Kurdistan

In order to Evaluation of variability and estimation of genetic variance¡ heritability of some important economic traits related to grain and fruit, especially fruit oil and combining ability of Pistacia atlantica female trees this research project was executed in 2 pattern habitats in Kurdistan, including Mazewanband (Baneh) and Dezli (Srvabad). In each habitat total 30 female trees relatively uniform, healthy, juicy with ability of fruit production were selected and their positions were recorded. In late October of each sample tree, numbers 10 reached 200 g of fruit harvested and were transferred to the laboratory for measuring data for the desired traits. Meanwhile, part of the samples to each tree merged with a sample of 500 g per tree for measuring oil percentage by method of Soxhlet were sent to analysis laboratory. Analysis of variance using method of "Nested" performed and Duncan test was used for mean comparisons. The genetic variance (σ2 g) of traits estimated through mean squares estimation and for additive genetic variance(σ2 A) of traits, Design І (North Carolina Designs) was used. broad-sense (h2 b) and narrow- sense (h2 n) heritability of traits and general combining ability (GCA) of trees and also fruit oil regression coefficients on the other were estimated. Analysis of variance showed showed significant differences (p ≤ 0.01) between pattern habitats (Srvabad and Baneh) for all studied traits and also among femal trees within the habitats in terms of all traits except fruit size . The total mean of seedless fruit percentage (SLFP) was equivalent to 20.83%, the average fruit length (FL) and fruit width (FWi), were 5.41 and 6.33 mm respectively, fruit size (fruit width * length) (FWi*FL) equivalent to 34.48 mm square, The total mean of weight of complete fruit (FW), seedless fruit (SLFW), barkless fruit (fruit without skin) (BLFW) and seed (SW), were 2.15 , 1.46, 1.47 and 0.51 g respectively, ratio of seed weight to fruit weight (SW/FW) was 0.24 and percent of oil content (OC%) mean was 26.86 %. Average of all studied traits except fruit oil in Baneh was more than Srvabad. With review of the ecological properties of habitats in different years showed that many factors, including genetic characteristics of the trees (male and female flowers mature time, incompatibility, etc.), existence of male and female trees with suitable number and combination, the ability of male trees to produce fertile pollen, characteristics of habitats, such as topographical conditions, amount and direction of land slope, soil moisture and other climatic characteristics such as temperature during pollination and fertilization (high and low temperatures), the occurrence and intensity of precipitation, humidity, direction and speed of wind, occurrence of living environmental stresses (insects and diseases of the flowers) and non-living (cold, heat etc.) are effective on the pollination , fertilization and fruit formation in Terebinth trees (Pistacia atlantica).The broad-sense (h2 b) and narrow- sense (h2 n) heritability of seedless fruit percentage (SLFP) were equivalent to 0.43 and 0.29, average fruit length (FL) were 0.82 and 0.70 , fruit width (FWi) were 0.79 and 0.67, fruit size (FWi*FL) equivalent to 0.76 and 0.58, weight of complete fruit (FW) were 0.61 and 0.42, seedless fruit weight (SLFW) were 0.82 and 0.76, barkless fruit weight (fruit without skin) (BLFW) were 0.60 and 0.45, seed weight (SW) were 0.48 and 0.36, ratio of seed weight to fruit weight (SW/FW) were 0.50 and 0.39 respectively. The broad-sense (h2 b) heritability of percent of oil content (OC%) was 0.72 too that represents the contribution of genetic factors in fruit oil inheritance and the possibility to improve fruit oil by means of breeding methods such as selection. The trees with numbers of 22, 9, 23, 17 and 18 with fruit oil content of 31.8, 29.2, 29.05, 28.35 and 28.05 percent respectively in Baneh and the trees with numbers of 6, 18, 10, 13 and 22 with fruit oil content of 35.45, 34.4, 34.35, 34.25 and 33.95 percent respectively in Srvabad showed the highest general combining ability (GCA) with the most fruit oil content among half- sib (HS)families within the habitat.The result of regression analysis of oil content on the other traits as independent variables showed that, the regression coefficient of oil content on barkless fruit weight (fruit without skin) (BLFW) and seed weight (SW) were positive and significant (p ≤ 0.01), on seedless fruit percentage (SLFP) and seedless fruit weight (SLFW) were were negative and significant(p ≤ 0.01) and on ratio of seed weight to fruit weight (SW/FW) was positive and significant (p ≤ 0.05). Thus, we can improve the oil content percentage of trees by selection of the high barkless fruit and seed weight (SW) and ones.