Autotoxicity of chard and its allelopathic potentiality on germination and some metabolic activities associated with growth of wheat seedlings

In this study, the allelopathic effect of aqueous whole mature chard plant extract (Beta vulgaris L. var.Cicla) on wheat (Triticum vulgare L. var. Sides 1) and an associated weed (chard) was investigated.Plants used were sampled in 2006, and then plant extracts were obtained after they were ground and processed with distilled water. Twenty five of wheat grains and the same number of chard seeds ofuniform size and weight were placed in a mixture on sterile filter paper in 15 cm Petri-dishes. Treated Petri-dishes were each supplied with 20 ml extract of 0.25,1, 4, 8, and 12% (w/v) while untreated controlwas supplied with 20 ml of distilled water. After 10 days the germination percentage, vigour value, seedling growth criteria and some physiological processes were counted. The aqueous extract retardedthe germination of chard more effectively than that of wheat and the effect was concentration dependent. The lowest concentration stimulated the germination of both wheat and chard; on the otherhand, the germination was retarded under the application of concentrations above 1%. However, 1% concentration had a positive effect on wheat and negative on chard. HPLC analyses of the watersoluble extract of whole chard plant residue revealed the presence of eight phenolic aglycones that show the abundant of chichimec acid, (+) camphor, hydroxybenzoic, p-coumaric and vanillic acids aswell as trace amounts of coumarin and protocatechuic acids. This extract may be used as a bioherbicide to control the germination and growth of itself (autotoxicity)

Trichoderma lixii ID11D seed biopriming mitigates dose dependent salt toxicity in maize

PEHLIVAN, NECLA/0000-0002-2045-8380WOS: 000396112600014Certain number of commercial products has been developed to grow stress resistant plants for the sustainability of agriculture in current era with full of energy dependency and hunger besides global warming. Given the risk of these products on the microbial environment in the rhizosphere and food security of mankind due to the accumulated chemical pollution through the food web, organic fungal plant growth promoting agents might be used. Hence, effects of Trichoderma lixii ID11D (TXD), our local fungal isolate on Zea mays L. cv. Samada 07 as a seed biopriming agent was investigated under dose dependent NaCl stress in this study. Fungus was characterized based on ITS (internal transcribed spacer) regions via clustering approach after isolated from tea plantation area. the higher the NaCl concentration, the more effective the TXD was observed. Improved electron transport rate (ETR), maximum quantum efficiency of PS II (Fv/Fm), the effective quantum yield of PS2 (Phi PS2), photochemical quenching (qP) and decreased non-photochemical quenching (NPQ) was detected in TXD primed plants after NaCl expose. TXD seed biopriming increased the lengths, fresh and dry weights of root/shoots and decreased the lipid peroxidation (MDA) remarkably. Non-enzymatic pathway was found to be more effective than enzymatic one for seed bioprimed plants proven by higher RWC, soluble protein, proline, chlorophyll, carotenoid, and less H2O2 and MDA levels under each dose of NaCl. Detected phenotypic and biochemical improvements pave the way of the potential usage of the formulated fungus biopreperations as a pre-harvest agent in agriculturally important cereals in the future and going beyond lab-based level.Recep Tayyip Erdogan University Research FundRecep Tayyip Erdogan University [2012.102.03.3, 2015.53001.102.03.07]This work was financed by the Recep Tayyip Erdogan University Research Fund (Project Numbers: 2012.102.03.3 and 2015.53001.102.03.07). We thank PhD candidate Sule Guzel for her valuable help