In recent decades, spring frost considered a serious threat in pistachio production (Pistacia vera). Considering that, Iran is one of the most important centers of pistachio production and has the highest variety of pistachios in the world, the identification of domestic and wild different rootstocks and their crosses to reach cold-tolerant rootstocks could be one of the effective solutions to face the challenge of spring frost. In this study, cold tolerance was assessed in fourteen rootstocks of pistachio domestic species (Badami Zarand, Sarakhs and Qazvini), interspecific hybrids (Qazvini×Khinjuk, Qazvini×Mutica, Qazvini × Baneh Baghi, Qazvini × Atlantica, Qazvini× Integerrima), non-domesticated species (Atlantica (P. atlantica), Integerrima, Khinjuk, Sarakhs, Mutica (P. atlantica sub. mutica) and Baneh Baghi (P. mutica × P. vera)) and UCB1 hybrid rootstock at low temperatures (4, 0 and -4 °C) for 2 hours. This experiment was conducted in a factorial completely randomized design with three replications on one-year-old seedlings in greenhouse conditions. The results showed that the rate of ion leakage, malondialdehyde and injury index percentage was significant (p <0.01) and their values were decreased in the cold-tolerant rootstocks than the cold-sensitive rootstocks. The interaction between treatments showed that the temperature of - 4 °C caused a significant reduction in ion leakage and malondialdehyde in the cold-tolerant rootstocks. Proline was increased in the cold-tolerant rootstocks compare to cold-sensitive rootstocks. The results of cation leakage percentage were significant in temperature and rootstocks (p <0.01). The results showed that the highest percentage of cation leakage related to potassium and there was a positive and significant correlation between calcium and magnesium and cell membrane stability. According to the results, the most sensitive rootstock was UCB1, Integerrima, Khinjuk and Baneh Baghi, respectively. Hybrids Qazvini , Baneh Baghi, Khinjuk and Integerrima rootstocks were significantly reduced under low-temperature stress. Mutica, Qazvini×Mutica, Sarakhs, Qazvini, Qazvini×Atlantica rootstocks, improved physiological and biochemical traits and maintained cell membrane integrity and finally showed greater tolerance to frost and freezing temperatures, which can be considered in the breeding program. پرونده مقاله

Pistachio is one of the most important and strategic crops in Iran which is typically cultivated under relatively saline soils and hot weather conditions. The present paper represents the results of an experiment which mainly focused on evaluating the tolerance of pistachio female and male genotypes to salinity stress. This experiment was carried out at the greenhouse of the Pistachio Research Center at Kerman, Iran, during 2016. The hybrids obtained from crosses between 17 male genotypes with a female genotype “Fandoghi” and also the combinations of 19 female genotypes after crossing with a male genotype “M15” were cultured in a completely randomized design with three replications under salt stress (4.2 dS m-1) without drainage in the greenhouse condition for a period of four months. The results show an increasing of the average soil salinity in pots to 32 dS m-1.The results also indicate that salinity might negatively affect growth parameters of pistachio. Therefore, selecting genotypes in this condition might lead to release tolerant genotypes. During the research, some yielded hybrids indicated the higher values for morphological parameters, the lower and higher concentration of Na+ and K+ under salinity stress, respectively. Meanwhile, it was found that, ‘Khanjari Damghan’ and ‘Mohseni’ among female parents, and M10, M15, and M25 among male parents are possible tolerant genotypes for further assessment in the area and also for releasing new rootstocks. The analysis of two clusters, i.e., cluster 1 (‘Khanjari Damghan’, ‘Mohseni’, ‘Lak Sirizi’, ‘Ebrahimi’, ‘Sifadini’, ‘Badami Zarand’, ‘Sephid Peste Nogh’, and ‘Post Kaghazi’) and cluster 2 (M10, M15, M24, M25, and M26) for female and male genotypes, respectively, exhibits that higher morphological parameters and also higher tolerance to salinity. More importantly, the analysis showed that these two categorized sets of genotypes can be proper choices for future breeding programs or to use directly in salinity conditions. پرونده مقاله