No abstract

This study evaluated the effect of Pseudomonas strains and arbuscular mycorrhiza fungi (AMF) in enhancing strawberry yield and phenolic and antioxidant capacity on a phosphorus (P) deficient calcareous soil. The experiments were conducted in three replicates with six treatments (four Pseudomonas strains, AMF and control) and three rates of P-fertilizer (0, 75, 150 kg P ha-1). Application of higher phosphate rates decreased total antioxidant capacity, total phenolic and flavonols content, whereas AMF and Pseudomonas strains increased quality and P concentration of fruit. The use of AMF and Pseudomonas strains resulted in better quality when used along with 75 kg P ha-1. These results demonstrated that the rhizospheric microorganisms improved the quality of fruit, especially when they applied in combination with lower rates of chemical fertilizers. Therefore, application of these microorganisms in sustainable agriculture is recommended.

In this study, seed yield production and its different components fruit length, fruit diameter, fruit length/fruit diameter ratio (FL/FD), diameter of flesh, diameter of seed core, fruit weight, weight of 1000 seed from 24 lines of pumpkin grown in Iran was examined. Twenty-five characters in all plant lines were measured by Descriptor (UPOV) and data were subjected to cluster analysis. Results showed that plants lines were divided in four groups. In all groups, regression comparisons were made for modeling the effect of different characters on seed yield, results also showed that fruit weight and fruit length in all groups had the most direct effect on seed yield. In conclusion, these traits are suggested as the best indirect selection criteria to improve the seed yield genetically in Cucurbita spp. genotypes especially in preliminary generation of breeding and selection programs.

Rice cultivation in Iran has a special place and its cultivation area is about 640,000 ha. Soil salinization is one of the most factor in reducing of grain yields and cultivation of paddy rice. Currently, half of Iran's cultivated lands (9.5 million ha) are affected by salinity, which has a major impact on crop yields. For this purpose, an field experiment conducted with the use of microorganisms (Pseudomonas putida strain S34, Pseudomonas fluorescens strain R167, Arbuscular mycorrhizal fungi (AMF) (Rhizophagus irregularis), co-inoculation of P.putida + P.fluorescens + AMF, and a non-inoculated treatment as control) on two rice cultivars (Hashemi and Gilane) in saline and normal soil in north of Iran during the 2018 and 2019. The results showed interactions of microorganisms and soil condition could alleviate the adverse effects of salinity by decreasing H2O2 (14-71% in normal soil and 44-281% in saline soil) and increasing catalase (CAT) activity (39.5-65% in Gilane and 45-61% in Hashemi), proline (17-46% in Gilane and 13.5-52% in Hashemi) and nitrogen (N) concentrations (12-27% in normal soil and 7-23% in saline soil) of leaves. Also microorganisms significantly increased tiller, panicle and grain number plant -1 , and biological and grain yield (23-44.5% and 32.5-56% in normal and saline soil, respectively). Furthermore, the greatest mitigating effects were observed in treated by P.putida + P.fluorescens + AMF plants. This study indicated that P.putida + P.fluorescens + AMF synergistically mitigate harmful impacts of soil salinity in rice cultivars.