نشریه نهال و بذر
سال سی و هشتم شماره 3 (پاییز 1401)

To identify salinity tolerant cultivated genotypes, 50 barley genotypes originated from Iran were evaluated in a field experiment during 2019-2020 and 2020-2021 cropping seasons in Yazd; Optimum experiment at Yazd central field station, and stress experiment in Ardakan field station, Iran. Six improved barley cultivars; Mehr and Khatam (Salinity tolerant), Nosrat, Nimrooz, Yousef and Gohran were also included in the experiments. The experiments were carried out using 8×7 rectangular lattice design with three replications. Phenological traits, grain yield and 1000-kernel weight were measured in all genotypes under optimum and salinity stress conditions. The electrical conductivity of soil and irrigation water in optimum condition was 3.4 and 3.6 dS m-1, and in the salinity condition, it was 14 and 10 dS m-1, respectively. The stress intensity index (SI) was 0.21 and 0.32 in 2019-20 and 2020-21 cropping seasons, repectively, which indicated higher stress intensity in the second year in the stress experiment. The mean grain yield under optimum and salt stress conditions in 2019-20 was 215 and 174 g m-2, respectively. In 2020-21 cropping season, mean grain yiled under optimum stress conditions were 271.9 and 184 g m-2, respectively. Combined analysis of traits showed that the of year × salinity stress × genotype interaction effect was significant on evaluated traits. Based on the results of principle component analysis and stress indices in 2019-20 cropping season, genotypes no. 50 (TN5008), 33 (TN4247) and 38 (TN4357) were superior genotypes. While in 2020-21 cropping season genotypes no. 24 (TN3474) and 27 (TN3643) together with salinity tolerant barley cultivars; Khatam and Mehr had higher grain yield. The collecting site of these two genotypes is Kerman province and Fars province, respectively. Based on the results of this research, tolerant cultivated barley genotypes were identified for further studies.

Since there is no information available regarding crop management, including proper planting arrangement and optimal planting density, of the imported shattering tolerant sesame genotypes, field experiments were carried out in research fields of Seed and Plant Improvement Institute, Karaj, and Khorasan Razavi Agricultural and Natural Resources Research Center, Mashhad, Iran, in 2019 and 2020. The effect of experimental factors including; 30, 45 and 60 cm inter row spacing, and 5, 8, 11 and 14 cm intra row spacing were evaluated as split blocks (strips) arrangements in randomized complete block design with three replications. The results showed that there was reduction in number of sub-branches in both locations due to reduction in inter row spacing and intra row spacing. On the other hand, the reduction in plant density m-2 increased the number of capsules plant-1 and seed number capsule-1. The highest seed yield (1342 and 604 kg ha-1 in Karaj and Mashhad, respectively) obtained from the 45 × 8 and 45 × 11 planting arrangement in Karaj and Mashhad, respectively. Generally, the results indicated that there is an optimal planting arrangement and planting density for each location. Therefore, due to increased competition between plants in high plant density and lack of proper utilization of resources in low plant density, it would not be possible to attain the highest yield potential of shattering tolerant sesame genotype in high and low plant density.

Study of adaptability and performance are important steps in the introduction of new olive cultivars for target regions. In this research, pomological characteristics, fruit and oil yield of 55 foreign and native olive cultivars were evaluated at Tarom olive research station from 2015 to 2017. The results showed that the effect of year, cultivar and their interaction effect on fruit yield were significant (P≤ 0.01). Cv. Toffahi with an average fruit weight of 11.36 grams had the largest fruit followed by cv. Jlot, cv. Chalkidiki and cv. Voliotiki with average fruit weight of more than 10 grams. Cv. Jlot had the highest fruit flesh (93%) and cv. Khodeiri had the highest (69.53%) dry matter oil content. Cv. Chalkidiki, cv. Nebali, cv. Arbequina, cv. Agromanaki, cv. Megaron, cv. Koroneiki with 66.28-55.67 percent dry matter oil content were among the cultivars with high oil content. The highest fruit yield per tree (80.16 kg tree-1) obtained from cv. Caridolia. Cv. Abusatl, cv. Moussaabi, cv. Arbequina, cv. Koroneiki, cv. Caridolia and cv. Conservolia were also high yielding with high yield stability cultivars, respectively. The highest oil yield belonged to cv. Caridolia, cv. Koroneiki and cv. Conservolia with 2974, 3412 and 2782 kg ha-1, respectively. Cv. Picual, cv. Chalkidiki and cv. Abusatl also produced more than two tons of oil per hectare.

Severe cold is one of the most important limiting factors for olive production. This research aimed to evaluating and selecting cold-tolerant olive cultivars. Therfore, six olive cultivars including; Grossane, Abusatl, Koroneiki, Chavar, Siab and Kolafaraj were evaluated under five cold treatments (Control, -9°C, -11°C, -13°C and -15°C). Electrolyte leakage, leaf thickness and relative water, nitrogen, calcium, potassium, total carbohydrate, oleic and linoleic acids contents of the leaves of olive cultivars were measured. The results indicated that the lowest leaf thickness related to cv. Koroneiki with average of 0.42 mm. The highest total carbohydrate was in the leaves of Grossane (4.83%) and the lowest in Koroneiki (2.20%). The cultivar × cold treatment interaction effect showed that in the -9°C, the highest changes in electrolyte leakage, as compared to the control temperature, was in cv. Siab (53.26%) and Koroneiki (48.59%). At the -11°C, the highest electrolyte leakage related to Kolafaraj (73.39%). There was significant difference between cold treatments for electrolyte leakage. As the temperature decreased to -15°C, electrolyte leakage increased. Mean comparison showed that cv. Abusatl (60.0%) and Grossane (60.86%) had the lowest electrolyte leakage. Correlation coefficient between oleic acid and linoleic acid contents was negative and significant (r = -0.490*). Relative water content had positive and significant correlation coffeieceint (r = 0.533*) with leaf potassium content. Leaf thickness had positive and highly significant correlation with oleic acid (r = 0.878**), and significan with linoleic acid (r = 0.545*). Correlation coefficient between total carbohydrate and linoleic acid was positive and significant (r = 0.804**). Based on the results of this research cv. Abusatl and Grossane were cold tolerant, and cv. Koroneiki, cv. Siab and cv. Kolafaraj were cold sensitive.

High yield and yield stability across a range of environmental conditions is one of the main objectives of crop breeding programs. In this study, white sugar yield stability of nine sugar beet cultivars commercially released in Iran from 2011 to 2020 with an introduced foreign cultivar as check was evaluated using randomized complete block design with four replications in six research field stations; Karaj, Ardabil, Kermanshah, Mashhad, Moghan, Miandoab, in four cropping seasons 2017-2021. The combined analysis of variance revealed that effects of genotype, year, location, and year × location, genotype × year, genotype × location and genotype × year × location were significant (p ≤ 0.01) on white sugar yield. Analysis of genotype × environment interaction showed that the first seven components were significant (p ≤ 0.01). Based on AMMI1 analysis, cv. Asia, cv. Shokoufa and cv. Arta had white sugar yield stability. Linear mixed model analysis showed that the effects of genotype and genotype × environment interaction were significant (p ≤ 0.01) on white sugare yield. Based on the BLUP method, cv. Perfecta, cv. Asia and cv. Shokoufa had the highest predicted mean value of white sugar yield. Biplot of white sugar yield with the WAASB index showed that cv. Asia, cv. Arta and cv. Shokoufa had higher sugar yield as well as higher white sugar yield stability. Ranking of sugar beet cultivars based on WAASB/white sugar yield ratio identified cv. Arta, cv. Asia and cv. Shokoufa as high yielding with white sugar yield stability. Simultaneous ranking and selection of cultivars based on 50:50 WAASB/white sugar yield ratio resulted the same. Therefore, cv. Asia followed by cv. Shokoufa and cv. Arta had relatively higher WAASBY indices. Considering the results of this study, cv. Asia, cv. Shokoufa and cv. Arta were identified as high yielding with higher white sugar yield stability.

To study the effect of plant density and planting arrangement on yield and bulb size of two onion cultivars, a filed experiment was carried out as split factorial arrangement in randomized complete block design with three replications in the research field of Seed and Plant Improvement Institute, Karaj, Iran, in 2018-2019. Two onion cultivars, Morvarid and Zargan, were assigned to main plots, and inter row spacing of 10, 15, 20 cm and intra row spacing of 5, 7.5, 10, 12.5 cm as factorial were randomized in sub plots. Cv. Morvarid and cv. Zargan had the highest marketable yield in 15 × 7.5 and 15 × 10 cm planting arrangements (88.8 and 66.7 plant m-2, respectively) with 73.7 and 67.6 t ha-1, respectively. In cv. Morvarid and cv.Zargan, with decreasing the plant density, the proportion of small bulbs decreased from 38.31 to 6.57% and from 64.12 to 7.77%, respectively. In cv. Morvarid, with decreasing the plant density, large bulbs, doubles and thick neck bulbs increased from 3.19 to 19.85% and from 7.92 to 29.41%, respectively. In cv. Zargan, with decreasing the plant density to 66.7 plant m-2 (15 × 10 cm), the proportion of medium size bulbs increased from 35.87 to 80.15%. During the storage period, cv. Morvarid had lower percentage of bulb sprouting and decay than cv. Zargan in all planting arrangements. The results of this research showed that in cv. Morvarid and cv. Zargan, planting arrangements of 15 × 7.5 cm and 15 × 10 cm, respectively, could be recommended to onion producers, because less seedlings are required for transplantation when compared with higher plant densities.