Germination characteristics of plump and shriveled seeds of Tamarix ramosissima matured in different seasons

Tamarix ramosissima has bi-seasonal flowering and fruiting. Although the basic germination characteristics of T. ramosissima seeds have been evaluated, there is a lack of information about the effects of seed plumpness on germination. Effects of seed plumpness and season of maturity and light conditions on germination were tested. Plump seeds matured in spring or summer had similar size and pappus length. The size of plump seeds was significantly larger than that of shriveled seeds. Both types of seeds matured in summer germinated better than seeds matured in spring. Germination percentage of plump seeds was significant higher than that of shriveled seeds, especially for seeds matured in spring. Darkness significantly decreased the germination of seeds matured in summer. This study provides comprehensive information about the seed germination requirements of T. ramosissima and the results can be used in restoration of desert lands.

Fire-Related Cues Significantly Promote Seed Germination of Some Salt-Tolerant Species from Non-Fire-Prone Saline-Alkaline Grasslands in Northeast China

Seed germination in response to fire-related cues has been widely studied in species from fire-prone ecosystems. However, the germination characteristics of species from non-fire-prone ecosystems, such as the saline-alkaline grassland, where fire occasionally occurs accidentally or is used as a management tool, have been less studied. Here, we investigate the effects of different types of fire cues (i.e., heat and smoke water) and their combined effect on the seed germination of 12 species from the saline-alkaline grassland. The results demonstrated that heat shock significantly increased the germination percentage of Suaeda glauca and Kochia scoparia var. sieversiana seeds. Smoke water significantly increased the germination percentage of Setaria viridis and K. scoparia seeds. However, compared with single fire cue treatments, the combined treatment neither promoted nor inhibited seed germination significantly in most species. These results suggest that fire cues can be used as germination enhancement tools for vegetation restoration and biodiversity protection of the saline-alkaline grassland.

In vitro assessment of elevated soil iron on germinability and germination characteristics of Sorghum bicolor (L.) Moench after chemo-priming

The commercial importance of Sorghum (Sorghum bicolor (L.) Moench) has attracted breeders to increase its seed yield using various breeding approach. Adverse soil factors however hampered progress made in crop development, especially micronutrient toxicity. Plant growth stimulators (PGS) have a significant role in enhancing growth parameters in Sorghum. In the present study, seeds were primed in 50, 150, and 250 ppm of each of gibberellic acid, indole acetic acid, and ascorbic acid respectively for 1 hr before sowing in Petri dishesmoistened with 10 ml of the iron-rich solution obtained as filtrate from a mix of distilled water and ferruginous soil (1:1 v/w). Results showed that although germination percentage in ferruginous medium was significantly reduced, there was enhancement in germination percentagewhen the seeds were primed in gibberellic acid (GA). Germinability in the iron-rich medium was 31.2 hrs; this was significantly reduced to 19.6 to 21.1hrs when these seeds were primed with growth stimulators.Although, shoot length was significantly reduced in plants exposed to ferruginous solutions, the root parameters were however enhanced. They were no significant changes in the total number of root branches regardless of ferrugenic status or use of growth stimulating agents. The utilization of growth stimulators as priming agents is called for to reduce stress impacts imposed by ferruginous soils during germination.

Study of the allelopathic effects of Medicago sativa on the germination characteristics of Secale montanum

This study investigated the allelopathic effects of Medicago sativa L. on the germination characteristics of weed rye (Secale montanum L.) Guss. In order to study the allelopathic effects of different concentrations of aqueous extract (0, 10, 20 and 30%) of different M. sativa parts (root, leaves, stem and aerial parts of the plant including (stems, leaves and flowers) on initial growth of rye (S. montanum) seedlings a factorial experiment arranged in RCB design was carried out with three replications in the greenhouse of Agricultural College, Mahabad Islamic Azad University in 2017. The greenhouse data showed that the plant height, root and biomass dry weight of the weed decreased so that the declining trend had a significant effect (p≤0.05) on all traits of rye studied in the present experiment. Among the aqueous extracts of M. sativa that of the root had the greatest allelopathic potential.

Influence of seed priming on germination characteristics of sorghum (Sorghum bicolor L. Moench)

Seed priming or invigoration is presowing treatments of improving germination aimed to reduce the time from sowing to emergence and improving emergence uniformity. Research on seed priming was conducted Indonesian Cereal Research Institute (ICERI) seed laboratory from January until March 2021 to evaluate the effect of seed priming on sorghum seed vigor. Seed quality parameters includes germination percentages, germination rate, shoot and primary root length, seedling dryweight, Sorghum seed variety of Suri 4 were used as seed material. Results showed that among the priming treatments that give positive effect on germination percentage, germination rate, seedling dry weight were priming treatment with KNO3 1.5%.

Effect of Walnut Extract on Germination Characteristics of Several Species of Weeds

Some plants can prevent seed germination and growth in other plants by producing toxic allelochemicals materials. this study aimed was to effect of walnut extract on germination characteristics of several species of weeds. The experiment was conducted in factorial based on a completely random design with three replications. The treatments of the experiment were two walnut cultivars, four species of weeds) Soutani, Rajal, Khardel and Zivan) and four levels of walnut extract (0, 10, 20 and 30 percent). Results showed that there was a significant difference among walnut extract concentration, weed species, and interaction between them for all studied traits (P< 0.01). In present study with increase the concentration of walnut extract from zero to 30%, in all four types of weeds the germination rate, germination percentage, root, stem and seedling length, and seed vigor index were significantly reduced. Also in the treatment of 30%, walnut extract species of Khardel showed the highest, and Shoufan, Rajal, and Zivan showed the lowest germination rat, germination percentage, root, stem, and seedling length, and seed vigor index.

Differences in Germination of ACCase-Resistant Biotypes Containing Isoleucine-1781-Leucine Mutation and Susceptible Biotypes of Wild Oat (Avena sterilis ssp. ludoviciana)

Herbicide resistance can affect seed germination and the optimal conditions required for seed germination, which in turn may impose a fitness cost in resistant populations. Winter wild oat [Avena sterilis L. ssp. ludoviciana (Durieu) Gillet and Magne] is a serious weed in cereal fields. In this study, the molecular basis of resistance to an ACCase herbicide, clodinafop-propargyl, in four A. ludoviciana biotypes was assessed. Germination differences between susceptible (S) and ACCase-resistant biotypes (WR1, WR2, WR3, WR4) and the effect of Isoleucine-1781-Leucine mutation on germination were also investigated through germination models. The results indicated that WR1 and WR4 were very highly resistant (RI > 214.22) to clodinafop-propargyl-contained Isoleucine to Leucine amino acid substitution. However, Isoleucine-1781-Leucine mutation was not detected in other very highly resistant biotypes. Germination studies indicated that resistant biotypes (in particular WR1 and WR4) had higher base water potentials than the susceptible one. This shows that resistant biotypes need more soil water to initiate their germination. However, the hydrotime constant for germination was higher in resistant biotypes than in the susceptible one in most cases, showing faster germination in susceptible biotypes. ACCase-resistant biotypes containing the Isoleucine-1781-Leucine mutation had lower seed weight but used more seed reserve to produce seedlings. Hence, integrated management practices such as stale seedbed and implementing it at the right time could be used to take advantage of the differential soil water requirement and relatively late germination characteristics of ACCase-resistant biotypes.

Effects of Water and Nitrogen Addition on the Seed Yield and Germination Characteristics of the Perennial Grass Leymus chinensis (Trin.) Tzvel

The reproductive characteristics of plants are likely affected by climate change e.g., changes in precipitation patterns and nitrogen deposition, but few studies have examined the effects of these ecological agents of selection on the seed yield and germination characteristics of perennial grasses. Here, we conducted a multiple-year pot experiment with Leymus chinensis, a common perennial grass in the eastern region of the Eurasian steppe zone, which was grown under three water treatments with and without nitrogen addition. The seed yield of L. chinensis increased with precipitation and was highest (7.0 g/pot) under 747 mm of precipitation with nitrogen addition (10.5 g/m2). Seed yield was positively correlated with heading number, tiller number, and grain number per spike, and the heading number was a critical factor affecting seed yield. Seed germination percentage and the time to obtain 50% germination were affected by environmental cues experienced by the mother plants.