Endosperm Protein of Wheat Seed as a Determinant of Seedling Growth

Abstract

Seed of a Mexican semidwarf wheat (Triticum aestivum L. cv. Inia 66), was obtained from a nitrogen fertilizer field trial grown in Mexico. A high positive correlation was obtained between seed protein content and seedling dry weight after 3 weeks growth (r = +0.92**). The seedling dry weight was positively related to the protein content of the aleurone layer and endosperm, but not to the embryo. Small, 35 Studies have shown that seed source, size, and protein content of both monocotyledonous and dicotyledonous species are positively related to early seedling growth and sometimes to economic yield (5, 9, 10, 14-16). In wheat, seed size affects seedling vigor, particularly when plants are grown under nonstressing conditions. Some field studies using high plant densities have shown similar results (3).McFadden (13) suggested that the chemical composition of seed can be an important factor in determining seedling vigor when seeds of the same cultivar are obtained from different sources. Other studies have shown high positive correlations between both seed protein and its constituent amino acids, and seedling dry weight during the first 3 weeks of development (11,12). Factors other than protein content of the seed have also been shown to be related to seedling vigor (1, 2). However, this research was conducted with aging seed. As intact cereal grains age they lose their ability to metabolize glucose into CO2, polysaccarides, and proteins (1). Anderson and Abdul-Baki (2) showed that changes in respiration and glucose utilization in embryos and endosperms do not proceed at the same rate nor go in the same direction during deterioration. The objective of this study was to determine which part of the wheat seed is responsible for the positive relationship between seed protein and seedling growth by using seed containing different quantities of protein due to nitrogen applications in the field. MATERIALS AND METHODSStandardization of Seed Material. Seed of a Mexican semidwarf wheat (Triticum aestivum L. cv. Inia 66) was obtained from a fertilizer trial conducted in Mexico during the 1970 season. Seed from each of the seven samples, from plots receiving fertilizer applications in the range of 0 to 300 kg N/ha2, were individually weighed to 40 ± 2 mg, milled, and assayed for total protein by an automated Kjeldahl procedure (7). Ten seeds from each fertilizer treatment were sown in plastic pots containing vermiculite for growth analysis. After 10 days, stands were thinned to six seedlings per pot; at the same time 100 ml of a one-half strength Hoagland's nutrient solution (8) containing 3 mi NO3-was applied. The seedlings were grown for 21 days at 25/15 C with 16-hr daylength and a light intensity of 13.5, 9.0, 3.6 ,uw/cm2-nm in the blue, red, and far red ranges respectively. Dry weights were determined on root and shoot material.Protein Determinations on Seed Parts. Forty seeds (40 + 2 mg) from each of the seven plots were placed in a humid atmosphere for 48 hr and then dissected into embryo, endosperm, and aleuro...

Reciprocal effect of parental lines on the physiological potential and seed composition of corn hybrid seeds

“…Since the seeds were not submitted to stress, were not subjected to different storage conditions, and were not imbibed when sampled, the greater quantity of albumins in lot 24 can only indicate that this difference arose during seed development. Differences in seed soluble protein content have been determined to contribute to altered seed vigour previously (Lowe and Ries, 1973;Strelec et al, 2007;Borba et al, 2014) and seed storage reserve amounts, including protein, are known to be influenced by the maternal parent (Letchworth and Lambert, 1998).…”

“…Amino acids produced from hydrolysis of the storage proteins can also be deaminated and, along with starch and lipid reserves, catabolized for energy production. In this way, greater storage reserve amounts in seeds can result in seedlings with greater vigour (Lowe and Ries, 1973;Bortolotto et al, 2008;Carvalho and Nakagawa, 2012). In addition, problems realizing full physiological potential in seeds can lead to poor desiccation tolerance (Hay and Probert, 1995;Faria et al, 2004).…”

Efeito do tamanho das sementes de trigo no desenvolvimento inicial das plantas e no rendimento de grãos

“…A habilidade das sementes grandes em produzir plântulas maiores é mais pronunciada em condições de baixa disponibilidade hídrica (Mian & Nafziger, 1994), alta salinidade (Grieve & Francois, 1992), semeadura profunda (Mian & Nafziger, 1994) ou baixo suprimento de N pelo solo, aumentando, assim, a importância das reservas da semente como fonte de nutrientes para o crescimento inicial da planta (Lowe & Ries, 1973). O tamanho da semente, em muitas espécies, é indicativo de sua qualidade fisioló-gica (Popinigis, 1977).…”

Ammonium nitrogen in soil solution and seed nitrogen affect the percentage of establishment of rice plants in submerged soil

“…Seed nitrogen content is also an important determinant. It was reported that the increase of seed nitrogen content enhanced the seedling growth (Fox and Albrecht 1957;Schweizer and Ries 1969;Lowe and Ries 1973;Metivier and Dale 1977;Rahman and Goodman 1983;Lieffering et al 1996;Hara and Toriyama 1998). However, to our knowledge, there are no reports on the effect of seed nitrogen content on the percentage of establishment except a report on wheat (Fox and Albrecht 1957).…”