جستجوی مقالات مرتبط با کلیدواژه "رسیدگی بذر" در نشریات گروه "آبخیزداری، بیابان، محیط زیست، مرتع"

Coronilla varia L., crown vetch, has wide adaptation, and desirable morphological characteristics for a grazing plant, tolerates short periods of overgrazing, and accordingly has potential as a forage crop. In this study, 15 traits were investigated to assess the morphological diversity of 52 populations using univariate and multivariate analyses. Crown vetch seeds provided by the Natural Resources Gene Bank of Iran were sown in an experiment field of Research Institute of Forests and Rangelands, Alborz province, over two years (2019–2020). Based on the flowering date, two taxa C. varia var. varia (as perennial that go to flowering in the first year) and C. varia (as perennial that go to flowering in the second year) were identified. However, a close relationship was found between local and exotic crown vetch populations. The populations were significantly variable in all traits. The high variability was found among populations for plant height, plant canopy, internode length, stem number, and biomass yield. Biomass yield was statistically significant (p < 0.05) and positively correlated withlant height (r=0.63) and plant canopy diameter (r=0.48), internode length (r = 0.57), stem number (r=0.66), and pod length (r=0.52). The principal component analysis showed that the variations observed in the populations were mainly caused by traits such as plant height, stem number, the number of days to 50% flowering and seed ripening indicating that their contribution was important in discriminating the populations. Direct selection can also be made for the populations with high biomass yield based on the recorded performance of these populations during the field experiments. In C. varia, 12 populations classified in cluster 1 with the highest values for 12 out of 15 traits could be useful for including in future breeding programs. Besides, in C. varia var. varia, population Bojnurd (for plant height and canopy diameter), population Rezvanshahr (for internode length and stem number), and populations Karaj1 and 2 (for biomass yield) had higher mean values and were recommended for breeding programs.

Salicornia herbacea is a sensitive species to seed shedding. In order to determine the effect of harvesting date on seed shedding, seed germination and seed oil production, an experiment was conducted in Gomishan Lagoon rangelands, Golestan province, Iran. Seed samples were harvested in twenty 1 m2 plots in 12 times since Nov 6th as the initial date of seed setting until Dec 21st as the final stage of seed maturity in 2019. Sampling was first carried out once a week and increased to every two days at the end of sampling dates. In each plot, the number of shrubs, visual evaluation of plant color changes from green to red, and brown coupled with the weight of the spilled seeds were recordedon each sampling date. Then, the required amount of seeds was randomly taken for the germination test and oil extraction. The obtained data were analyzed using PAST software. The results of analysis of variance showed significant differences between sampling dates on seed germination and oil percent (p <0.05). The highest and lowest germination rates with average values of 91% and 98% were obtained in the initial and final stages of harvesting, respectively. Also, the highest and lowest oil yield with average values of 19% and 16% was obtained in the middle and final stages of seed maturity. The results of multivariate analysis showed significant relationships between the seed shedding and plant color (green, red and brown) (p <0.05). According to the results, among the visible plant traits, the brown color (dryness) in up to 60% of the plants had the lowest shedding rate and was recommended as a good indicator for determining the suitable date to harvest Salicornia herbacea seeds.