No abstract

Sesame (Sesamum indicum L.) is a summer crop and its production is threatened by drought stress (WS) due to increased aridity and higher temperature worldwide. Breeding sesame accessions that are more tolerant to WS is therefore highly important for sustainable seed production. Here, 21 accessions representing 12 sesame‐growing countries were evaluated with yield and quality traits under two different water‐regime treatments as non‐stressed (NS) and WS. The combined analysis of variance revealed that there was a significant variation among the accessions for all agronomic traits. We also found that the effects of treatment and genotype were significant for the quality traits of oil content, stearic acid, oleic acid, linoleic acid, and linolenic acid. The t‐test of significance for mean values indicated that there were significant differences between the treatments for plant height, number of branches, number of capsules, and seed yield. The highest yield was found in PI 170735 with the value of 25.6 g/plant in the treatment of WS. The higher values were observed for oil content in NS treatment, the highest amount of oil content was recorded as 53.9% for PI 207664. In addition, higher grand mean was observed for oleic acid under WS treatment. Principal component analysis using the five agronomic traits indicated that 76.60% and 71.18% variability accounted for the first two principal components (PCs) with eigen values ≥ 1 in WS and NS treatments, respectively. The diverse accessions characterized with agro‐quality traits can be used in further improvement programs to develop new drought‐tolerant cultivars.

Diaspores (samaras) of the sheoaks, Casuarina and Allocasuarina, have a mesocarp composed of hydrophilic fibres that, in Allocasuarina, rapidly expand on wetting, capturing significant quantities of water. The ecological function of this water capturing has been the subject of speculation but not quantification or experimentation. Therefore, the rate and quantity of water absorbed, and the floatation properties of samaras of accessions of Casuarina and Allocasuarina were assessed. Casuarina absorbed water slowly (~48 h) with median absorption of 90% (by weight) whereas Allocasuarina absorbed water rapidly (<2 min) with median absorption of 240%. The process was reversible and increasing in Allocasuarina, with median absorption reaching 400% over three to five wetting/drying cycles. The floating half-life of Casuarina and Allocasuarina samaras overlapped, 17-70 and 29-57 h, respectively, so Casuarina samaras were not shown to be better adapted to hydrochory. Based on five accessions of each genus, it does not be appear that water-capturing of sheoak samaras is directly related to habitat aridity, nor to potential hydrochory. Therefore, the ecological implications of differential water-capturing of sheoak samaras remains to be determined.

Bermudagrass is one of the most commonly used warm-season turfgrasses worldwide. In the present study, the tolerance to drought stress by applying farmyard manure and biological seed coating preparations containing Trichoderma harzianum, Bacillus subtilis and Bacillus megaterium in bermudagrass were assessed. Seeds of Gobi (registered cultivar) were used as plant material. Gobi were planted in 2 different growing media (A = garden soil + river sand + peat, B = garden soil + river sand + farmyard manure). Uncoated grass seeds were sown in the A group growing medium, while coated seeds were sown in the B group growing medium. As the coating material, which is a new generation seed coating preparation containing Trichoderma harzianum, Bacillus subtilis and Bacillus megaterium, was preferred. To create drought stress [T0 (0), T1 (25%), T2 (50%) and T3 (75%)], 4 doses of irrigation regimes were determined. The traits of clipping yield, shoot dry weight, root dry weight, leaf burning and turfgrass quality were all affected by levels of drought stress. However, farmyard manure and seed coating mitigated the adverse effects of drought stress.