News Update on Wheat Seedling : May 2022

Winter Wheat Seedling Emergence from Deep Sowing Depths

Growers in low-precipitation (<300 mm annual) dryland wheat-fallow areas of the inland Pacific Northwest need winter wheat (Triticum aestivum L.) cultivars that emerge from deep sowing depths in dry soils. Stand establishment is the most important factor affecting winter wheat grain yield in this region. Despite poor resistance to disease, modest grain yield potential, and other problems, the outdated soft white winter wheat (SWWW) cultivar Moro is widely sown in these dry areas, due to its excellent emergence ability. All other SWWW cultivars are semidwarfs that carry emergence-impeding Rht1 or Rht2 reduced-height genes. From 12 sowing trials at 2 locations over 4 yr, we compared the emergence capability of Moro to (i) 8 SWWW cultivars and (ii) 16 SWWW advanced experimental Mororeplacement lines. Under both wet and dry soil conditions (soil water content in the seed zone ranged from 11 to 19 mm3 mm−3), seeds were sown deep, with 110 to 160 mm of soil cover. Moro always emerged fastest and achieved the best final stand compared with the semidwarf cultivars. The advanced experimental lines, which contained either no reduced-height gene or a Rht1, Rht2, or Rht8 reduced-height gene, had superior straw strength, disease resistance, and grain quality compared with Moro. The best-emerging advanced experimental lines had coleoptile lengths >100 mm. Coleoptile length was associated with emergence capability among both cultivars (r2 = 0.71, P < 0.004) and advanced lines (r2 = 0.62, P < 0.001). From deep sowing depths in this study: (i) cultivars and advanced lines with Rht1 and Rht2 reduced-height genes always emerged poorly compared with Moro; (ii) the Rht8 reduced-height gene did not hamper emergence to the extent that Rht1 and Rht2 did; and (iii) several advanced experimental lines with long coleoptiles equaled or exceeded Moro for emergence. [1]

Technical improvements in two-dimensional electrophoresis increase the level of genetic variation detected in wheat-seedling proteins

The level of genetic variation revealed by two-dimensional electrophoresis of proteins from seedlings of two wheat lines strongly depends on the technical procedures. Improvements in extraction and electrophoresis procedures relative to earlier experiments on the same material led to a significant increase in the genetic variation revealed: 15.2 % instead of 6.7 % of the spots were genetically variable. The improved procedure is based on (i) precipipation of proteins from wheat seedlings with trichloroacetic acid and acetone, (ii) solubilization of the proteins with a solution containing urea, potassium carbonate and sodium dodecyl sulfate, (iii) isoelectric focusing in an optimized pH gradient, obtained with a mixture of carrier ampholytes (Pharmalyte and Servalyt), and (iv) running elecrophoresis in the second dimension on gels with increased surface. [2]

Relative Date of Wheat Seedling Emergence and Its Impact on Grain Yield

Emergence of wheat (Triticum aestivum L.) seedlings usually occurs over a period of several days, resulting in nonuniformity among neighboring plants. The impact of nonuniformity in time of emergence on grain yield has not been determined. We determined effect of planting depth on relative date of seedling emergence, and of relative date of emergence on grain-bearing tillers and grain yield per plant. Large seed (39.8 ± 4.59 mg kernel−1) in 1989, and large (41.7 ± 3.83 mg kernel−1) and small seeds (24.3 ± 4.56 mg kernel−1) in 1990 were obtained from ‘Roblin’ wheat. Seeds were hand.planted at 25-, 50-, and 75-mm depths on Neuborst clay loam (fine-loamy, frigid, Aquic Haploborolls) at Portage la Prairie, MB. Plants were tagged the day they emerged, and individual plant yield was determined at harvest. Planting depths did not differ for total percent emergence in 1989, but in 1990, increasing planting depth led to decreased total emergence. Gompertz growth model predictions of inflection time, maximum emergence rate, and cumulative percent emergence indicated that seedling emergence rate decreased as planting depth increased, and the decrease was greater with small seed than with large seed. The first date on which seedlings emerged each year was designated as Day 1. Averaged across 2 yr, plants that emerged on Day 1 to 3 produced 1.4 times the yield of those emerged on Day 4 to 6, and 3.2 times the yield of those emerged on Day 7 to 9. Reduced yield of late emerged plants was due primarily to fewer grain-bearing tillers. This research demonstrates the benefit of shallow placement of large seeds in minimizing variation in time of seedling emergence among plants, and increasing grain yield. [3]

Seed and Seedling Performance of Bread Wheat (Triticum aestivum L.) as Influenced by Rate and In-Season Nitrogen Application

Field and laboratory experiments were conducted in the wheat growing belt of south-eastern Ethiopia to assess effects of rate and in-season N application on seed and seedling performance of local and improved bread wheat varieties. For the field experiments, a factorial combination of four N levels, two bread wheat varieties, and three times of N application were laid out in a Randomized Complete Block Design with three replicates. Laboratory tests were conducted in a Completely Randomized Design with four replicates to evaluate seed germination capacity and seedling vigor. The rate and timing of N application had significant (P = .01) effects on seed hectolitre weight, seed germination capacity and seedling vigor index. 1000-kernels weight was not affected by the rate of N application but significantly influenced by time of N application. Three times split application of N at 120 kg ha-1 resulted in significantly (P = .01) higher hectolitre weight, percentage of normal seedlings, seed germination speed, seedling dry weight and vigor index compared to the other treatments. The results revealed that application of 120 kg N ha-1 in three-split doses with ¼ dose at planting, ½ dose at mid-tillering and ¼ dose at anthesis led to enhanced seed quality and seedling performance of the crop[4]

Assessment of Concentrations of Nano and Bulk Iron Oxide Particles on Early Growth of Wheat (Triticum aestivum L.)

Aims: In this work we assessed Fe2O3 nanoparticles with bulk Fe2O3 for possible phytotoxicity and stimulative effects on wheat seed germination and early growth stage.

Methodology: The treatments in the experiment were five concentrations of bulk (100, 500, 1000, 5000 and 10000 ppm) and five concentrations of nanosized Fe2O3 (100, 500, 1000, 5000 and 10000 ppm) and an untreated control. Germination tests were performed according to the rule issued by ISTA. Analysis of variance (ANOVA) was performed between treatment samples. The information was analyzed using MSTAT-C computer software. Means compared by multiple range Duncan test and a 95% significance level (p < 0.05) was employed for all comparisons.

Results: Results showed that exposure of seeds to 100 ppm iron oxide nanoparticles indicated the greatest germination rate (by 41% more than control group) related to other treatments. Increasing nanoparticles concentration above 100 ppm reduced seed germination rate. It has not found any significant effects by bulk and nanoparticles on elongation of shoot, root and seedling of wheat. Application of 100 ppm concentration of nanosized Fe2O3 reduced mean germination time (MGT) by 38.5% in comparison to the control, while 100 ppm concentration of bulk Fe2O3 did not decrease MGT in comparison with the control. The highest root biomass was achieved from concentration of 100 ppm nano- Fe2O3, but an increased concentrations of nanoparticles Fe2O3 significantly reduced root weight. Nevertheless, on the basis of these results it is highly recommended that the influence of low dose nanomaterial be assessed in order to encourage seed germination and seedling growth.[5]


Reference

[1] Schillinger, W.F., Donaldson, E., Allan, R.E. and Jones, S.S., 1998. Winter wheat seedling emergence from deep sowing depths. Agronomy Journal, 90(5), pp.582-586.

[2] Damerval, C., De Vienne, D., Zivy, M. and Thiellement, H., 1986. Technical improvements in two‐dimensional electrophoresis increase the level of genetic variation detected in wheat‐seedling proteins. Electrophoresis, 7(1), pp.52-54.

[3] Gan, Y., Stobbe, E.H. and Moes, J., 1992. Relative date of wheat seedling emergence and its impact on grain yield. Crop Science, 32(5), pp.1275-1281.

[4] Deressa, H. and Nigussie-Dechassa, R., 2013. Seed and seedling performance of bread wheat (Triticum aestivum L.) as influenced by rate and in-season nitrogen application. Journal of Experimental Agriculture International, pp.857-870.

[5] Feizi, H., Moghaddam, P.R., Shahtahmassebi, N. and Fotovat, A., 2013. Assessment of concentrations of nano and bulk iron oxide particles on early growth of wheat (Triticum aestivum L.). Annual Research & Review in Biology, pp.752-761.

Leave a Reply

Your email address will not be published.

Previous post Astrophysics and Logic Often Conflict
Next post Study on Geochemical Exploration and Processing Studies for Graphite and Tungsten Minerals from Burugubanda-Tapaskonda Areas of East Godavari District, India