JWSS - Journal of Water and Soil Science

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Seed traits are an important measure of the effects of endophytic fungi in Festuca genus. In this study, endophyte-infected (E⁺) and un-infected (E^-) clones of the same tall fescue genotypes were used to investigate the effects of endophyte on the seed production and associated traits. Endophyte infection resulted in 32.8% increase of total seeds by weight, 34.6% seeds per plant, and 30.6% panicles per plant, but other seed components were not affected by endophyte. Significant phenotypic variances were observed for traits except for 1000 seed weight. Plant genotype×fungal status interactions occurred for seed per plant. These interactions occurred largely because of variation in different plant genotypes. Genetic variance for this trait in E⁺ was greater than E^- for both years, suggesting that the endophyte can mask plant genotypic variance. The results indicated that endophyte had a positive effect on seed production but could result in overestimating of plant genetic variance for some traits. In conclusion, breeding strategies should consider presence or absence of endophyte and the possible effects on variances.

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Fescues (Festuca spp) are widely distributed in the temperate regions and are used for turf, forage and soil conservation. Though seed traits are important measures of the effects of endophytic fungi on their host, little information is available in this respect for Festuca. In this study, endophyte-infected (E⁺) and endophyte-free (E^-) clones of the six fescue genotypes were used to investigate the effects of endophyte on seed production. The relationships between seed traits plus direct and indirect effects of components on seed yield were also studied. Endophyte infection resulted in 38.1% to 249% more seed yields in some genotypes, though some were not affected by this symbiotic relationship. Correlations between traits and also results of stepwise regression were influenced by the presence of the symbiotic fungi. Path analysis showed that endophytic fungi changed direct and indirect effects of components on seed yield. In endophyte containing clones, panicle fertility had the most direct effects and number of panicle per plant and seed per panicle the most indirect effects on seed yield. In E- clones, panicle fertility had the highest indirect effects and other components had direct effects on seed yield. The results suggested that breeding strategies for increasing seed yield in fescue should consider the presence or absence of endophyte in germplasm.

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The purpose of this study was to measure daily and seasonal evapotranspiration and daily crop coefficient of two common varieties of sunflower (Sirna and Euroflor) via drip-tape irrigation system. For this purpose, the sunflower water use was determined by daily monitoring of soil moisture at the depths of 10, 20, 30, 40 and 60 cm, and the crop evapotranspiration (ETC) was measured using volume balance method. According to the equation recommended by FAO, the obtained value of KC for Euroflor and Sirna varieties at the initial stage was 0.32. According to volume balance method, the Euroflor KC value for development, middle, and late stages were found to be 0.75, 1.18 and 0.9 and for Sirna were found to be 0.72, 1.15 and 0.84 respectively. Seasonal amount of evapotranspiration for Euroflor and Sirna varieties was equal to 601 and 575 mm, which was 26 and 30 percent less than seasonal ET0 in Isfahan. The average value of during the sunflower growing season was 0.77, which was greater than that offered by Doorenbose and Pruitt (0.55). As the crop coefficients of two varieties were different during the growing season and they were also different from FAO KC, measuring the actual amount of KC as a function of growing degree days can increase the accuracy of the estimated ETc and help develop the crop models in order to improve the irrigation management.