Influence of Different Environments on Germination Parameters and Seedling Morphology in <i>Khaya senegalensis</i>(Desr.) A. Juss (Meliaceae)

Khaya senegalensis is one of the largest and most majestic trees in Africa. Overexploited for its precious wood and medicinal values, the natural stands of this species are in danger of extinction in Cote d’Ivoire. Its sustainable management through regeneration techniques and assessment of its degree of adaptation to the changing climate is necessary. The aim of this study is to evaluate the effect of different environments on seedling germination and development in Khaya senegalensis. A total of 2160 seeds from different mother plants and 540 individuals from seed germination were selected and evaluated. The trials were conducted on three sites that were distinct by their microclimate (two nurseries in Cote d’Ivoire and one greenhouse in France). Analysis of variance showed that germination and morphology parameters were not influenced by the characteristics of the mother plants used (p > 0.05), but rather by the study sites (P < 0.05). The stable and controlled greenhouse climate was more advantageous for latency time (12.66 ± 0.80 days), germination delay (16.96 96 ± 0.54 days), germination speed (19.66 ± 2.95 days), germination duration (10.83 ± 2.27 days) and germination rate (88.88 ± 7.97) with more vigorous sowing than the other two sites. The results showed in general that the higher the height of the seedlings, the thicker the diameter of the seedlings (r = 0.796) and the higher the number of leaves (r = 0.946). This savannah species is native to the arid zones of Africa, but this study highlighted its adaptive potential to changing and different climates. These results are decision support tools for the regeneration of native pioneer forest species with high agroforestry potential and socio-economic importance such as Khaya senegalensis. This study could be extended to other species in order to restore disturbed ecosystems.

Effect of Low Gamma Irradiation on the Germination and Morphological Characteristics of Broad Beans (Vicia faba L.), Mung Beans (Vigna radiata L.), and Peas (Pisum sativum L.) Seedlings

Understanding the effects of ionising radiation (IR) on plants has been a major focus of research. Acute high-dose effects are well-documented and understood (mainly through laboratory testing). Lower doses, on the other hand, are less understood, as low dosage research is controversial, and there are only a few studies that use low and ecologically relevant IR levels, particularly those conducted under controlled conditions. The effect of low gamma radiation was investigated in this study using Vicia faba L., Vigna radiata L., and Pisum sativum L. Healthy and viable seeds of these plants were irradiated with varying doses of gamma radiation (Cs−137 source) and sown under controlled environmental conditions. The doses/dose rates used were within the scope of the International Commission on Radiological Protection’s Derived Consideration Reference Level (DCRL) for these groups of plants (1 - 10 mGy∙d−1), so this study tested this DCRL. Observations were made on certain germination parameters and growth traits like germination percentage and rate, shoot and root length, seed weight, number of leaves, wet and dry biomass, plant height, leaf chlorophyll content, and leaf area. In the germination phase, the doses employed in this experiment did not affect the seeds’ weight, germination percentage, and rate, but there were some interesting effects on the root and shoot length;as all irradiated groups performed better than the control group (particularly the 16.2 mGy and 48.5 mGy dose in V. radiata and P. sativum, while the 1070 mGy dose had the highest value in V. faba). However, the plants were able to compensate for the effects observed in the germination phase and by the end of the experiment, there were no statistically significant effects (at 0.05 p level) in all the morphometric parameters studied;the visible organs appeared normal, and growth rate was normal. This study, therefore, concludes that the DCRL used to protect these groups of plants from the effects of IR (1 - 10 mGy∙d−1) is appropriate and present regulation appears to be suitable.

Does Cold Plasma Affect Breaking Dormancy and Seed Germination? A Study on Seeds of Lamb's Quarters(Chenopodium album agg.)

Low-pressure discharge is applied for stimulation of germination of two seed lots of Lamb＇s Quarters （Chenopodium album agg.） with different starting germinations （17%, 8%） and in different stages of dormancy. Different exposition durations with cold plasma treatment were applied. The variable of the ratio cumulative germination was calculated. The Richards＇ equation was used for curve-fitting and simulation of the growth curves. Population parameters, namely Vi - viability, Me - time, Qu - dispersion, and Sk - skewness, counted from the curves described the germination rate well. Significant differences among Qu confirmed the erratic dormancy and gradual germination of Lamb＇s Quarters. No difference in the Me parameter was found between two tested seed lots, and no interspecies characteristics were changed using low-pressure discharge. The results suggested that plasma treatment changed seed germination in Lamb＇s Quarters seeds.

Effect of low power laser irradiation on bio-physical properties of wheat seeds

The production of quality food is indispensable and essential to overcome its global shortage.In order to exercise the facile route to acquire massive production,a laser irradiation treatment method was established.We have investigated the effects of diode laser irradiation on wheat seeds germination,its early growth and biochemical parameters.The variation in germination parameters,caused by laser treatment were monitored carefully.A comparison study was accomplished to examine the laser irradiation effects on treated and control seeds.The red laser indicated an enhancement of 25%in germination percentage,4.68 cm in shoot length,and 0.64 cm in root length while green laser showed 6.25%less germination percentage than the untreated seeds.Further green laser showed 9.67 cm increase in shoot length,5.39 cm in root length as compared to untreated seeds.It was found that the seeds which were irradiated with green laser showed an amount of superoxide dismutase(SOD),catalase(CAT)and peroxidase(POD),of 11.9,10,and 1.53 per mg of protein,respectively as compared to control seeds.Thus,these investigations are promising and suitable for upcoming research on a large scale.