Changes induced by osmotic stress in the morphology, biochemistry, physiology, anatomy and stomatal parameters of almond species(Prunus L. spp.) grown in vitro

We investigated the influence of different levels of osmotic stress on growth and development in selected wild almond species （eight Prunus spp.） grown in vitro. The study, while endorsing the efficacy of in vitro screening of auxiliary buds of wild almond for osmotic stress tolerance, showed species variability in its response to osmotic stress. Osmotic stress reduced growth and development of all the species. How-ever, the putative tolerant Prunus spp. showed better performance than the putative susceptible genotypes. On average there was an 80% de-crease in shoot dry weight at -1.2 MPa. Reduction in shoot weight was more common in osmotic stress-susceptible species in the section labeled‘Euamygdalus’. The tolerant Prunus species produced smaller changes in biochemical responses than the sensitive cultivars for malondialdehyde content, catalase activity, relative permeability of protoplast membranes, and net photosynthetic rate. The tolerant species maintained cell integrity better than drought sensitive species. Wild almond species in the section labeled ‘Spartioides’ （Prunus arabica （Olivier） Neikle, Prunus glauca＆amp;nbsp;（Browicz） A.E. Murray, Prunus scoparia Spach） and ‘Lycioides’ （Pru-nus lycioides Spach, Prunus reuteri Bossi. et Bushe） were best adapted to osmotic stress. Increase in chlorophyll concentration and leaf thickness under high osmotic stress can be considered as preliminary selection parameters for osmotic stress tolerance in Prunus spp. The study con-firmed the efficacy of the in vitro method for screening of large number of genotypes for osmotic stress tolerance in wild almond species.

Evaluation of seed quality and oil parameters in native Iranian almond(Prunus L.spp.) species

We assessed chemical composition and variation in oil content and seed weight of 40 wild-growing almonds（Prunus L. spp.） accessions collected from different parts of Iran. There were significant differences in kernel weight and oil parameters. Accessions ranged from0.20 to 1.5 g in kernel weight, 0.2–3.0 mm in shell thickness, and 16–55 % in oil content. The predominant vegetable oil components of kernels were 4.6–9.5 % palmitic acid, 0.4–0.8 % palmitoleic acid, 1.0–3.4 % stearic acid,48.8–88.4 % oleic acid and 11.3–33.2 % linoleic acid.Linolenic acid was detected in 15 accessions. High heritability was recorded for all studied traits and was maximum for shell thickness（98.5 %） and minimum for oil content（97.1 %）. Maximum and minimum ‘Euclidean＇pair wise dissimilarities were 17.9 and 0.5, respectively.All 40 accessions were grouped into two major clusters.