• Pistacia vera L. genotypes; a potential rival for UCB-1 rootstock for cultivating under salt stress conditions

      Raoufi, Ahmad; Rahemi, Majid; Salehi, Hassan; Pessarakli, Mohmmad; Univ Arizona, Sch Plant Sci (ELSEVIER, 2020-05)
      UCB-1(P. integerrima xP. atlantica) is considered as a high tolerant hybrid rootstock to salt stress from Pistacia genus that widely used as rootstock for pistachio cultivars. This study was conducted to compare the response of five P. vera salt-tolerant genotypes with UCB-1 under salt stress. The experiment was carried out as a completely randomized design with factorial arrangement and four replications. Eight months old pistachio genotypes namely Akbari, Ahmad-Aghaee, Italiyayi, Ghazvini, Badami, and UCB-1 were subjected to salinity stress at three salinity levels (0.5 (control), 12 and 18 dS m(-1)) for 75 days. In order to select the most tolerant genotypes, some physiological and biochemical factors were measured. Leaf water potential, chlorophyll, and K content decreased while leaf total proline, phenolic content, lipid peroxidation, antioxidant enzyme activities, and Na leaf content increased with raising salinity levels regardless of genotypes. Comparison between genotypes indicated that for most of the measured factors, UCB-1 and Akbari showed better performance comparing to others. However, there was no significant difference between Akbari and UCB-1 regarding salt tolerance that shows the high potential of P. vera genotypes to be used instead of UCB-1. Furthermore, there was no significant difference between Akbari, Ahmad-Aghaee, and UCB-1 in malondialdehyde (MDA) and total phenolic content as well as ascorbate peroxidase (APX) activity. In conclusion, the studied rootstocks can be ordered based on their tolerance to salinity as the following: UCB-1 = Akbari > Ahmad-Aghaee > Italiyayi > Ghazvini > Badami.
    • Salicylic acid regulates photosynthetic electron transfer and stomatal conductance of mung bean (Vigna radiata L.) under salinity stress

      Lotfi, Ramin; Ghassemi-Golezani, Kazem; Pessarakli, Mohammad; Univ Arizona, Coll Agr & Life Sci, Sch Plant Sci (ELSEVIER, 2020-07)
      The role of salicylic acid (0, 1 and 1.5 mM) on photosynthetic electron transfer chain of mung-bean plants grown under salt stress (0, 3, 6 and 9 dS/m(2)) was studied using chlorophyll a fluorescence (ChlF) measurements. Results indicated that accumulation of K+ content decreased but, Na+ content increased with increasing salt stress. SA-treated plants had more K+ and less Na+ content compared with the non-SA treated plants. Application of SA, especially with 1 mM, increased the I-P step of the OJIP transient curve of fluorescence. Salt stress decreased g(s), CCI, F-V, F-M, S-M and PIabs in plants. However, the time taken to reach FM (TFM) increased with increasing salt stress. Application of different concentrations of SA significantly improved gs, CCI, FV, SM, and PIabs of plants. Photosynthetic efficiency of plants improved as a result of SA application via decreasing F-o and increasing F-V/F-M, F-V/F-O, S-M/T-FM and Area under both saline and non-saline conditions. Accumulation of Na+ had negative, but K+ had a positive correlation with gs, CCI and most of the chlorophyll a fluorescence parameters (except, Fo and TFM). A positive correlation was found between g(s) and CCI with PIabs. This research indicated that low gs under saline condition seems to cause losses in PSII efficiency, but the application of SA with 1 mM concentration is the best treatment for the alleviation of salt stress injuries on PSII activity of mung bean plants.