Growth Properties Of Seedlings Research Articles

Effects of Some Heavy Metals on Germination and Seedling Growth of Sorghum

Heavy metal contamination in soils can adversely affect seed germination and seedling growth of most plants. This research was conducted to determine the effects of different doses (0, 100, 200, 400 and 800 mg L-1) of Ni (nickel), Cd (cadmium), Pb (lead), Cr (chromium) and Hg (mercury) on seed germination and seedling growth of sorghum. The study was conducted in laboratory conditions at the Agricultural Faculty of Akdeniz University in 2017. Sorghum cv. N48×Early Sumac was used as the plant material. In the research, germination rate (GR), relative germination index (RGI), mean germination time (MGT), relative vigor index (RVI), relative root length (RRL), relative shoot length (RSL), root fresh weight (RFW) and shoot fresh weight (SFW) were measured during germination and seedling growth to determine the effects of heavy metals. The results showed that both germination and seedling growth properties were adversely affected by heavy metals. In addition, while the negative effect of cadmium on germination properties was limited, it had serious negative effects on seedling characteristics of sorghum. Increasing heavy metal doses adversely affected all investigated properties. In conclusion, all heavy metals including Hg and Cd had negative effect on germination and seedling growth of sorghum in the study.

Comparative study on germination and seedling growth of wheat cultivars under salt stress regimes

Salinity interferes with germination and hampers the growth of wheat especially at seedling stage which necessitates determining of salt tolerant cultivars. Based upon the current situation a controlled experiment was carried out at the Laboratory of Horticulture, Faculty of Agriculture, Cukurova University, Turkey to comparatively evaluate wheat varieties response to imposed salt stress. Germination and seedling growth properties under salt stress were taken as response variables. The seeds of five bread wheat genotypes (‘Wafia’, ‘Lucilla’, ‘Envoy’, ‘Lok1’and ‘RSP- 561’) were placed in Petri dishes with salinity doses (Control (0), 4, 8 and 12 dS.m-1 NaCl) which were applied at germination and subsequent early seedling phases under laboratory conditions. The results revealed that root growth was highly sensitive to salt stress and the varieties of Envoy and Lucilla remained relatively tolerant to salt stress than other cultivars. The biochemical analysis revealed that proline content spiked with increasing salinity level, ‘RSP-561’ under 8 dS.m-1and 12 dS.m-1 recorded the maximum proline content. Salt stress boosted leaf proline content of salt sensitive wheat genotypes (‘Wafia’ and ‘Lok1’), whereas declined proline level was observed for salt tolerant cultivars. In addition, salt-sensitive genotypes showed a reduction in chlorophyll content a, b, total chlorophyll and carotenoid while, ‘Wafia’ and ‘RSP-561’ recorded the minimum Chlorophylls and Carotenoid contents. Further investigations are needed, however, to enhance understanding of the salt stress effects during the whole growing cycle of wheat.

Marker-based parental selection to improve performance of orchadgrass polycross populations under water deficit environments

Little is known about the application of parental molecular information to enhance the performance of synthetic populations of orchardgrass under water deficit environments. In this study, first generation progenies of four polycrossed groups constructed from a combination of several parental genotypes with contrasting levels of diversity (high and low phenotypic, high and low molecular) were assessed in a field trial for quantitative traits under normal and water stress conditions and in the laboratory for germination and seedling growth properties. To investigate genetic variation, the DNA from the selected genotypes were subjected to inter-simple sequence repeat and sequenced-related amplified polymorphism markers. The assessment of first generation showed a clear separation of the four progeny groups in both water environments indicating that the progeny performance depends on the level of diversity among the parental genotypes. Molecular distance was highly associated with progeny performances of all traits at both moisture conditions. Crosses between genetically distant parents led to significantly increased drought tolerance of progenies. Although significant associations between phenotypic diversity among polycross parents and progenies performance were found for some traits under normal conditions, no such relationship was observed under water stress conditions. The results indicated that the predictive ability of parental phenotypic distance was strongly affected by the target trait and moisture conditions. Superiority of first generation progeny from parents with high molecular diversity under both moisture conditions emphasizes the benefit of marker-assisted polycross breeding in orchardgrass.

Rhizobacteria cooperative effect against Meloidogyne javanica in rhizosphere of legume seedlings

Summary Root-knot nematodes are major pests of legume fields in Iran. This research evaluated the effect of Rhizobium leguminosarum bv. phaseoli and Pseudomonas fluorescens CHA0 (stand alone and combination treatment) on galling and reproduction of root-knot nematode, Meloidogyne javanica, in legum (chickpea, bean, lentil, pea) seedling rhizosphere, and the growth properties of the host plants. The legumes seeds were sown in 1kg sterilized sandy loam soil. Inocula were 5 J2/g of soil, in the case of the nematode, while considering the bacteria 1×107 cfu/kg soil. A treatment of nematicide (cadusafos) was performed, as a commonly used nematicide in Iran, at 2g/kg soil. Two months after inoculation, the following parameters were recorded: the number of knots, egg masses and reproduction factor of the nematode, bacterial nodules per root, and growth properties of seedlings in the treatments (control, nematode, nematode+nematicide, and nematode+rhizobacteria). The greatest bacterial effect on the control of the nematode was observed in the rhizosphere of the bean treatments. Inoculation with Rhizobium in the soil decreased the galling on the legumes’ roots, and the combined inoculation with Pseudomonas and Rhizobium resulted in a higher decrease of the galling.