Background: Flower development and sufficient fruit set are important parameters with respect to walnut yield. Knowledge about flowering genes of fruit trees can help to conduct better molecular breeding programs. Therefore, this study was carried out to investigate the expression pattern of some flowering genes (FT,SOC1,CAL,LFYandTFL1) in Persian walnut (cv. Chandler) during the growing season and winter dormancy.Results: The results showed that walnut flower induction and initiation in Shahmirzad, Iran occurred in early June and late September, respectively. After meeting chilling and heat requirement, flower differentiation and anthesis occurred in late-March and mid-April to early-May, respectively. Study of flowering gene expression showed that the expression of theFTgene increased in three stages including before breaking of bud dormancy, from late March to late April (coincided with flower differentiation and anthesis) and from late May to mid-June (coincided with flower induction). LikeFT, the expression ofSOC1gene increased during flower induction and initiation (mid-May to early-August) as well as flower anthesis (mid-April to early-May).LFYandCALgenes as floral meristem identity genes are activated byFTandSOC1genes. In contrast with flowering stimulus genes,TFL1showed overexpression during winter dormancy which prevented flowering.Conclusion: The expression ofFTgene activated downstream floral meristem identity genes includingSOC1,CALandLFYwhich consequently led to release bud dormancy as well as flower anthesis and induction. Also,TFL1as a flowering inhibitor gene in walnut showed overexpression during the bud dormancy. Chilling accumulation reducedTFL1gene expression and increased the expression of flowering genes which ultimately led to overcome dormancy.

Drought stress is one of the most important factors limiting the growth and productivity of fig (Ficus carica L.) in the Iran. Detailed knowledge about the biochemical responses of native figs to drought stress could contribute to the success of vegetation programs. Four cultivars of fig, ‘Deyme Ahvaz’ (Deym), ‘Sabz Estahban’ (Sabz), ‘Siah’ and ‘Shahanjir’ (Shah), were selected and subjected to drought by withholding irrigation for 14 days. Stressed plants were reirrigated and the recovery was studied for 7 days. Control plants were irrigated daily maintaining soil water content at about field capacity. The levels of pigments and non-enzymatic antioxidants as well as the activities of antioxidant enzymes were quantified. The results demonstrate that the four investigated fig cultivars showed a clear difference in their response to water stress and recovery. Under drought conditions, Deym exhibited higher pigments content and activities of antioxidant enzymes than other cultivars. Catalase had no major antioxidative function in fig. Water stress treatment significantly increased α-tocopherol concentration but decreased ascorbic acid content in the studied cultivars.

The aim of this study was to assess the effects of invertase and amylase enzyme activities on starch, individual sugars, and organic acid changes during developmental stages (before caprification, fruit set, softening, and senescence) in Ficus carica L.cv Sabz with three replicates. The initial stage of fruit development showed the highest stored carbohydrates and the lowest total sugar and whilst the senescence stage obtained the lowest stored carbohydrates and the highest total sugar. Furthermore, high-performance of liquid chromatograph analysis revealed that the value of glucose and fructose significantly increased as fruits developed. Citric acid was the most abundant organic acid followed by malic acid. Moreover, invertase activity increased sharply before the caprification stage up to the senescence stage. We found that fig fruit possess α- and β-amylase activities, which increased dramatically up to the ripening stage and then slightly decreased at the senescence stage. The present study showed that this cultivar is a rich fruit based on glucose and fructose as well as citric and malic acid.

The application of nano-iron chelate and iron chelate was evaluated in this study. The treatments were applied in mid-spring and mid-summer. The experiment was conducted using a completely randomized block design with three replications during 2013–2014. The results showed that applying two times spraying of nano-iron chelate 9% (2000 mg/L) can significantly increase leaf area, chlorophyll content, along with greater catalase enzyme activity. foliar application of two times spraying of nano-iron, 9% (2000 mg/L) were observed to cause increases in, total soluble solids (TSS), ascorbic acid and total phenol contents at the time of harvest. One time foliar spraying of nano-iron, 9% (2000 mg/L) and one time soil application of nano-iron chelate, 9% increased fruit firmness. Iron and calcium nutrients inside the leaves and fruits increased in amount as a result of applying two times spraying of nano-iron, 9% (2000 mg/L). We concluded that the foliar application of nano-iron chelate is more effective than iron-chelate in treating chlorosis and in enhancing the fruit quality of quince.

In Iran, the most pistachio orchards are located in semi-arid regions and irrigated with saline water which influences their growth and yield. The present investigation was conducted to evaluate the effects of salinity on growth, and morpho-physiological parameters of six pistachio genotypes as rootstock (ʽAkbariʼ, ʽAhmad-Aghaiʼ, ʽUCB-1ʼ, ʽItalyayiʼ, ʽGhazviniʼ and ʽBadamiʼ). Treatments were different salinity concentrations using NaCl at 0.5, 12 and 18 dSm-1 on six genotypes of pistachio. According to the results, by increasing salinity, the FW, DW, number of growing leaves, SPAD index of leaves, chlorophyll content and stomatal conductance were reduced, but electrolyte leakage of leaf and root tissues, soluble sugars and antioxidant capacity were increased. ʽUCB-1ʼ, ʽAkbariʼ and ʽAhmad-Aghaiʼ had the highest leaf area compared to other genotypes under salinity conditions. The lowest leaf abscission was belonged to ʽUCB-1ʼ and its difference was significant with other genotypes. The WUE of ʽUCB-1ʼ reduced and it was higher than ʽAkbariʼ. The growth of ʽUCB-1ʼ significantly declined up to 79.6% under salinity stress. Salinity stress had the lowest adverse effect on the growth of ʽAkbariʼ and ʽAhmad-Aghaiʼ genotypes. There was no significant difference among genotypes in regard to RWC under salinity stress. It can be concluded that ʽUCB-1ʼ, ʽAkbariʼ and to some extent ʽAhmad-Aghaiʼ were tolerant to salinity stress and can be recommended to use as rootstock under moderate salinity conditions.

Fruits is a scientific journal for original articles and reviews on fruit crops in temperate, Mediterranean, subtropical and tropical regions