نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی سابق کارشناسی ارشد، دانشکده کشاورزی و منابع طبیعی، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات، تهران، ایران.
2 مربی، پژوهشکده میوه‌های معتدله و سردسیری، موسسه تحقیقات علوم باغبانی، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
3 دانشیار، پژوهشکده میوه‌های معتدله و سردسیری، موسسه تحقیقات علوم باغبانی، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
4 استاد، دانشکده کشاورزی و منابع طبیعی، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات، تهران، ایران.
5 دانشجوی دکتری، پژوهشکده میوه‌های معتدله و سردسیری، موسسه تحقیقات علوم باغبانی، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
6 استادیار، پژوهشکده میوه‌های معتدله و سردسیری، موسسه تحقیقات علوم باغبانی، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Considering the extent of grapevine cultivation in arid and semi-arid areas of the world where salinity stress is one of the important environmental stresses that limits grape production in Iran. Therefore, this research was carried out for preliminary evaluation and comparison of the reaction of three grapevine native cutivars; Bidaneh Sefid, Bidaneh Ghermez, Shahroudi and three hybrids H4, H6 and Kober5BB rootstocks in response to salinity stress in Temperate Fruits Research Center, Horticultural Sciences Research Institute, in Karaj, Iran, in 2015 -2017. The experiments were conducted as factorial arrangements in completely randomized design with five replications under in vitro conditions. The effect of salt was evaluated to identify the most tolerant cultivar/rootstock at four concentration levels of sodium chloride (NaCl); 0 (control), 25, 50 and 75 mM. The results showed significant effect of different salt levels on grapevine cultivars/rootstocks for all vegetative traits including; length of shootlets, number of leaves shootlet-1 and leaf expansion. Most of these traits increased at mild salt stress up to 25 mM. However, at 50 and 75 mM, which are decisive concentrations for tolerance of plant tissues to salinity, the traits showed significant decreases. According to the vegetative growth charcteristics, H6 hybrid rootstock and cv. Shahroudi had relative tolerance to the salinity stress that was confirmed by high preservation of their chlorophyll content, as observed about 2 mg g-1 FW in H6 hybrid rootstock. The total protein and proline contents of leaves showed that the total protein content in all grapevine cultivars and rootstocks followed increasing trend with stress intensity. The proline content had an appropriate association with the higher tolerance level of H6 hybrid rootstock and cv. Shahroudi to 75 mM of sodium chloride.
Key words: Grapevine, Tissue culture, Sodium chloride, Total protein content, Total proline content.
Introduction
Salinity, as one of the abiotic stresses, affects the growth and production of agricultural crops by reducing the osmotic potential and creating osmotic stress, ion toxicity and nutritional imbalance in many regions of the world (Mahajan and Tuteja, 2005). Statistics show that about 1.13 billion hectares of crop plants are affected by salinity-alkaline stress worldwide, which includes about 20% of the total cultivated area in the world (Morton et al., 2019). Grape is known as one of the horticultural crops with high economic value in the world, and its ecological scope for development is very wide. According to the Food and Agriculture Organization of United Nation (FAO), the grape production in 2020 was 78 million tons. The cultivated areas and grape production in Iran are about 230 thousand hectares and 2.5 million tons, respectively, and stands 10th in ranking ladder in the world (FAO, 2020). The majority of grapevine cultivation is in arid or semi-arid areas where soil salinity and alkalization is a matter of serious concern due mainly to low rainfall and high evaporation, though different grapevine cultivars are relatively tolerant to salinity stress environments. This research was carried out with the aim of preliminary evaluation of the morphological characteristics and biochemical attributes contributing to resistance to salt stress of local cultivars and imported and rootstocks of grapevine under in vitro conditions.
Materials and Methods
Cultivars and rootstocks used in this research included three Iranian local grapevine cultivars; Shahroudi, Bidaneh Sefid and Bidaneh Ghermez and three rootstocks; two Iranian hybrid rootstocks, H4 (V. vinifera cv. Jighjigha × V. riparia cv. Gloire), H6 (V. vinifera cv. Gharaozum × Kober5BB), and one imported rootstock, Kober5BB (V. berlandieri × V. riparia). Applied salinity treatments were at four levels of sodium chloride; 0 (control), 25, 50 and 75 mM. Modified MS culture medium (Murashige and Skoog, 1962) enriched with 0.5 mg l-1 BAP was used to cultivate and establish explants. The experiment was conducted as factorial arrangements in completely randomized design with five replications. The most important traits that were evaluated included; shoot length, number of leaves, leaf area, proline and protein contents. Analysis of variance was performed using SAS software, and Duncan’s Multiple Range Test was used for mean comparisons at the 5% probability level. Graphs were made using Microsoft Excel
Results and Discussion
The tallest shootlet length was measured in the non-salinity stress conditions in cv. Bidaneh Sefid, cv. Shahroudi and H6 rootstock, respectively. Also, H4 and Kober5BB rootstocks had lower growth in non-stressed conditions compared with other cultivars and rootstocks. Mean comparison for the effect of salinity stress on morphological trait of leaf number at different levels of salinity stress; 0, 25, 50 and 75 mM, similarly showed that, in the absence of salinity stress, the number of developed leaves shootlet-1 varied from 7 to 12 leaves in H4 and H6 hybrid rootstocks, respectively.
The results of mean comparison for the effects of different salinity stress levels on leaf development showed that at 0 mM salinity level (control), a significant difference was observed between leaf expansion of cultivars and rootstocks. Normlly, leaf expansion under in vitro conditions is a function of the adaptability of genotype to tissue culture conditions as well as the type and level of growth regulators, the mode of use, and their interaction with internal plant hormones (Mansouryar et al., 2016). Mean comparison showed that with increases in salinity stress levels, the total chlorophyll content decreased in all studied cultivars and rootstocks. According to the results, at 75 mM salt stress in the culture medium, H6 hybrid rootstock, cv. Shahroudi, cv. Bidaneh Sefid and cv. Bidaneh Ghermez, Kober5BB rootstock as well as H4 hybrid rootstocks have the highest total chlorophyll content.
In general, the results of this research showed that the in vitro evaluation on grapevine cultivars and rootstocks by increasing the level of sodium chloride (NaCl) with concentrations higher than 50 mM, which in this research 75 mM, as appropriate approach for preliminary evaluation and screening of cultivars and rootstocks for tolerance to salt stress. Threfore, it is necessary to examine several growth characteristics including; length of shootlets grown in in vitro, leaf expansion and number of leaves, over time after application of salt stress treatments. Biochemical characteristics, especially the rate of decay and reduction of total chlorophyll, should also be used as useful attribute for screening and selection of tolerant grapevine cultivars and rootstocks to salinity stress. Therefore, in the further researches, it is necessary to confirm these findings, in pot and orchard, conducting experiments in saline soil conditions.
References
FAO. 2020. Statistics Yearbook. World Food and Agriculture. Food and Agricultural Organization. Rome, Italy. 351 pp.
Mahajan, S. and Tuteja, N. 2005. Cold, salinity and drought stresses: An Overview. Archives of Biophysics, 444, pp.139-158. DOI: 10.1016/j.abb.2005.10.018.
Mansouryar, M., Erfani-Moghadam, J., Abdollahi, H. and Salami, S. A. 2016. Optimization of in vitro micropropagation protocol for some vigorous rootstocks of pear. Iranian Journal of Horticultural Science, 47, pp.361-370. DOI: 10.22059/ijhs.2016.58537. (In Persian).
Morton, M.J., Awlia, M., Al Tamimi, N., Saade, S., Pailles, Y., Negrão, S. and Tester, M. 2019. Salt stress under the scalpel–dissecting the genetics of salt tolerance. The Plant Journal, 97, pp.148-163. DOI: 10.1111/tpj.14189.
)