Hossein Astaraki; Hossein Ramshini; Mahmoud Lotfi; Ali Izadi Darbandi
Abstract
Development of cultivars with high yield under normal conditions and maintaining their yield under abiotic stresses is the main purpose of plant breeding programs in arid and semi-arid areas. The present study aimed to evaluate the yield stability of a collection of commercial melon varieties under drought ...
Read More
Development of cultivars with high yield under normal conditions and maintaining their yield under abiotic stresses is the main purpose of plant breeding programs in arid and semi-arid areas. The present study aimed to evaluate the yield stability of a collection of commercial melon varieties under drought stress. The trial was conducted in a field under normal conditions (plants were irrigated after 50 mm evaporation of a class A evaporation pan) and drought stress conditions (irrigation was carried out after 100 mm evaporation of a class A evaporation pan). In average, 3.32 kg fruit/plant and 2.76 kg fruit/plant were obtained under normal and drought stress conditions, respectively. The highest reduction in yield as the consequence of drought exposure was recorded for 'Mazandarani' (52%) and 'Samsoori' (48%). The most drought-tolerant genotypes were 'Mamaghani', 'Nahavandi', 'Shadegan', 'Crenshaw' and 'Suski-e-Sabz' as they had constant yield under both growing conditions. On the other hand, 'Samsoori' and 'Saveh' were the most sensitive genotypes to drought. For most of the measured traits, the values of broad-sense heritability were over 0.50 i.e. there was a large genetic diversity among melon genotypes. This variation can be utilized for selecting high potential fruit yield and drought-tolerant genotypes. Total soluble solids (TSS) (ºBrix) was 15.2% for 'Honey-Dew'. TSS (ºBrix) was obtained 10.7, 10.09, and 9.2% for Iranian genotypes of 'Khatooni', 'Samsoori', and 'Saveh', respectively. In conclusion, although some Iranian melon genotypes were recognized as drought tolerant, they need to be improved for TSS (ºBrix).
Hamed Ebrahimzadeh; Mahmoud Lotfi; Mohammad Sadat-Hosseini
Abstract
Doubled haploid method via parthenogenesis induction still remained prominent in Cucurbitaceae breeding due to drastic reduction in time and cost of newly released lines. In this study, different doses of Gamma ray (25, 50, 75, 100, and 200 Gy) were used to irradiate pollen grains for induction of parthenogenetic ...
Read More
Doubled haploid method via parthenogenesis induction still remained prominent in Cucurbitaceae breeding due to drastic reduction in time and cost of newly released lines. In this study, different doses of Gamma ray (25, 50, 75, 100, and 200 Gy) were used to irradiate pollen grains for induction of parthenogenetic haploid embryos in oilseed pumpkin (Cucurbita pepo var. ‘Styriaca’). Parthenogenetic embryos at different developmental stages were rescued in vitro and 348 plants were obtained, of which 134 were recognized as haploid by ploidy analysis. The highest rate of haploid plants was obtained from globular (25.3%) and torpedo (23.8% plants) embryos followed by arrow-tip (13.4%), torpedo (10.5%), stick (10.5%), heart (9%), and cotyledonary (7.5%), respectively. All doses, except 200 Gy, were effective for induction of embryos and haploid plants; in a way that the highest number of haploids was obtained by 100 Gy. Our results indicated that parthenogenetic haploid embryos could be efficiently induced in C. pepo if proper Gamma ray dose and developmental stage of embryos are selected.
Navid Yazdani; Behnam Osanloo; Mahmoud Lotfi; Keyvan Asefpour Vakilian
Abstract
Digital image processing is an emerging tool to predict fruit quality; therefore present study was carried out to develop an image processing technique for investigating the storage life of cantaloupe. Potassium permanganate (KMnO4) impregnated materials were used to prolong the postharvest life of cantaloupe ...
Read More
Digital image processing is an emerging tool to predict fruit quality; therefore present study was carried out to develop an image processing technique for investigating the storage life of cantaloupe. Potassium permanganate (KMnO4) impregnated materials were used to prolong the postharvest life of cantaloupe fruit and the effects of these treatments were evaluated by 3 image textural features parameters and flesh firmness. The treatments were divided into seven groups containing untreated, conventional paper impregnated with 7% KMnO4, nanozeolite impregnated with 7% KMnO4 and nanosponge impregnated with 0, 4, 7 and 10% KMnO4 respectively in packages. Findings of the investigations showed that the nanosponges impregnated by 7 or 10% KMnO4 could preserve the quality of cantaloupe over time by maintaining its color and flesh firmness which could be a result of ethylene absorption. Nanozeolite covered with 7% KMnO4 was also a good compound to preserve the fruit firmness. Image processing features including Entropy was increased and Homogeneity was decreased during cold storage whereas, fruits that are treated with nanosponge impregnated with 10% KMnO4 showed less Entropy and more Homogeneity than other treatments. Moreover, all KMnO4 treated fruits had better values of flesh firmness and image textural parameters than control. A significant correlation was observed between flesh firmness and image parameters. In total, nano-materials showed acceptable performance in extending the postharvest life of cantaloupes based on the fruit firmness and our findings illustrated that the image processing technique can be used to assess the quality of cantaloupe fruits during storage.
Mansoureh Danesh; Mahmoud Lotfi; Shiva Azizinia
Abstract
Iran is a part of the secondary centre of origin of melons, and therefore, there is a wealth of genetic variation of these species in this country. The Amplified Fragment Length Polymorphism (AFLP) marker was applied to investigate the genetic variations among five major Iranian melon cultigens (Cucumis ...
Read More
Iran is a part of the secondary centre of origin of melons, and therefore, there is a wealth of genetic variation of these species in this country. The Amplified Fragment Length Polymorphism (AFLP) marker was applied to investigate the genetic variations among five major Iranian melon cultigens (Cucumis melo) and ‘Ananasi’ as a general well-known cultivar. Ten primer pairs were used on 90 individuals producing 318 polymorphic fragments, with an average of 31.8 fragments per primer combination. The polymorphism rates ranged from 80 to 100%. The genetic similarities among accessions were calculated according to Dice’s Similarity Index and used to construct a dendrogram based on the Unweighted Pair Group Method with Arithmetic Average (UPGMA). The genetic distance estimates based on AFLPs ranged from 0.29 to 0.63, with a mean of 47±0.3. Iranian melon genotypes and the ‘Ananasi’ cultivar were considered as two separate groups on the cluster analysis. The principal coordinate analysis showed a separate allocation of the melon cultivar groups. The results demonstrated a wide diversity of Iranian melon cultigens. The high number of alleles and the high expected genetic diversity detected with the AFLP marker indicated that the Iranian melon cultigens had distinctive characteristics and were an important genetic diversity pool, which made them a valuable source of breeding materials.
Amin Hassankhah; Kourosh Vahdati; Mahmoud Lotfi; Masoud Mirmasoumi; John Preece; Mohammad Hassan Assareh
Abstract
Plantlets grown in conventional tissue culture systems usually encounter physiological and anatomical abnormalities including inability to photosynthesize, low chlorophyll content, open stomata, lack of a cuticle layer in the leaf, abnormal xylem parenchyma etc. Photoautotrophic and photomixotrophic ...
Read More
Plantlets grown in conventional tissue culture systems usually encounter physiological and anatomical abnormalities including inability to photosynthesize, low chlorophyll content, open stomata, lack of a cuticle layer in the leaf, abnormal xylem parenchyma etc. Photoautotrophic and photomixotrophic systems could diminish these problems. The purpose of this study was to increase the chlorophyll content and photosynthetic ability of shoots grown in vitro and to improve the adaptation of walnut plantlets. Walnut apical leaf buds were cultured in vessels containing DKW medium supplemented with 0, 15, 30 and 45 g L-1of sucrose. The vessels were closed with a clear polypropylene lid with two syringe filters on the lid (V1) or with a 50 mm microporous polypropylene membrane (V2). Natural ventilation had a significant effect on most of the growth indices. Furthermore, different levels of sucrose had significant effects on growth characteristics. Natural ventilation increased chlorophyll content significantly. By using ventilated vessels containing 15 g L-1 sucrose, the total chlorophyll was significantly increased. Stomata under non-ventilated conditions were spherical with wide openings, whereas those in ventilated vessels were elliptical with narrow openings. As a result, ventilated vessels with 15 g L-1of sucrose produced healthy plantlets.
