Seed Phosphorus Content Research Articles

Identification of phosphorus starvation tolerant soybean (Glycine max) germplasms

In the present study, 156 soybean genotypes mainly from the Hebei growing-area were identified for their low phosphorus starvation tolerance. The results showed that the relative values (value of dry wt. in zero soil P/value of dry wt. in adequate soil P) of shoot dry weight and root dry weight of all soybean varieties, at the phosphorus concentration of 0 mmol·L−1 and 1.0 mmol·L−1 in supplied solution, offered a quick and reliable method to identify and classify genotypes for phosphorus starvation tolerance. We describe three classes: tolerant, moderate and sensitive P starvation groups which had 29, 59, and 68 cultivars, respectively. Eight varieties, Ji-dou11, Lu75, Hei-da-li, Zhong-huang15, Zhe98-14, Da-mao-jiao, Dahuang-dou and Zha-lai-te-qi were screened out for their high tolerance to phosphorus deficiency under zero soil phosphorus conditions. In addition, the relationships between soybean phosphorus starvation tolerance and seed phosphorus content, root morphology, rhizosphere acidification are also discussed.

Effect of copper fertilization on plant growth, seed yield, copper and phosphorus uptake in soybean (Glycine max) and their residual availability in Mollisol

: A field experiment was conducted during the rainy season of 1997 and 1998 to itudy the effect of copper fertilization on plant growth, seed yield of soybean [Ijilycine max (L.) Merr.], copper and phosphorus uptake and their residual ailability. Sixteen treatment combinations consisted of 4 varieties ( Bragg , PK 262 , PK 41 6 and PK 1042 ) as main plots and 4 copper levels (0, 2.5, 5 and 10 k4, Cutha) as subplot treatments were evaluated in split plot design with 3 replications. Application of 2.5 kg Cutha significantly increased the number of nodules and their dry weight, dry matter yieldlplant and leaf area index at 60 days, while leaf area index increased significantly up to 5 kg Cutha. The seed yield did not increase with copper application. However, the interactions between varieties and copper levels revealed that variety PK 416 at 5 kg Cu/ha gave the highest number of nodules, their dry weight, leaf area index and dry matter yield at 60 days, seed yield, pods/plant, seed copper and phosphorus uptake at harvest, while Bragg yielded lowest. Copper content in soybean seed was higher than its shoot. Shoot and seed phosphorus content and their uptake significantly increased with 2.5 kg Cu/ha and decreased with 10 kg Cu/ha. Copper application significantly increased the copper availability in soil at harvest, whereas the increase in available soil phosphorus was non significant in northern Indian Mollisols. Differential response of varieties revealed that PK 416 showed a trend . of increased growth an seed yield, while Bragg showed susceptibility to increasing copper and PK 1042 and PK 262 gave intermediate responses.

RESPONSE OF A LOCAL AND SOME EXOTIC MUNGBEAN VARIETIES TO BIO- AND MINERAL FERTILIZATION

A pot trial was carried out in the greenhouse of the National Research Centre during the summer season of 1999 to investigate the combined impact of Bradyrhizobium sp. (vigna) and Azotobacter vinelandii in the presence of various doses of chemical fertilizers, i.e. 25%, 50% and 100% of the recommended dose of NPK, on nodulation, growth parameters, seed yield and its components, and seed contents of protein, phosphorus and potassium of a local (Kawmy-1) and three exotic (VC-4, VC-9 and King) varieties of mungbean. The results indicated that there were no significant differences between the different varieties for nodule number per plant, while significant variations were obtained between both varieties and biofertilization treatments. The plants of the Kawmy-1 variety gave the shortest period of growth, the highest number of pods per plant and the highest values of harvest index and seed protein content. The King variety had the longest period of growth and the highest values for number of branches, seed yield, biological yield, seed index and seed phosphorus content. The inclusion of Azotobacter vinelandii significantly augmented various tested parameters, with the exception of seed yield, biological yield and potassium content, in comparison with Bradyrhizobium. Insignificant differences were found owing to the interaction between varieties, various levels of mineral fertilizers and types of biofertilizers with the exception of harvest index and seed phosphorus content.

Exudation of low molecular weight organic acids by germinating seeds of two edaphic ecotypes of Silene nutans L.

Two parapatric ecotypes of Silene nutans, exhibiting distinct allozyme patterns, morphology and autecology were investigated for differences in exudation of low molecular weight organic acids from germinating seeds, and for differences in seed phosphorus content. The calcicolous ecotype is restricted to calcareous soils, and the silicicolous one predominantly occurs on acid soils, and sometimes, although less frequently, on neutral to alkaline soils. No clear difference was found between ecotypes. However, within the silicicolous ecotype seed samples showed marked differences in exudation pattern and seed phosphorus content depending on origin along the soil acidity gradient. Seeds of low-pH origin exuded more dicarboxylic acids (malic + succinic acid, oxalic acid) and had a lower phosphorus content than seeds of high pH origin. The exudation of dicarboxylic acids from seeds of low pH origin is probably an adaptation to adverse conditions (aluminium toxicity) on acid soils. The pattern is similar to that found among different cultivars of wheat. It is contrasted to the pattern found on comparison of a suite of calcifugous and calcicolous species, where exudation of di- and tricarboxylic acids is associated with solubilisation of recalcitrantly bound phosphorus and iron in calcareous soils.

Influence of Seed Phosphorus Content on Seedling Growth in Wheat: Implications for Organic and Conventional Farm Management in South East Australia

ABSTRACTFertilizer trials involving application of phosphorus (P) as both rock phosphate and superphosphate were conducted on adjacent organic and conventional farms in SE-Australia in 1991 and 1992. Seed P concentration and seed P content (P concentration multiplied by seed mass) were higher on the organic farm in 1991 when rainfall was below average, but were higher on the conventional farm in 1992, a wetter year. Addition of superphosphate increased seed P content and concentration on both farms in 1991 and on the organic farm in 1992. These results indicated that seed produced on a conventional farm with addition of fertilizers containing soluble P is likely to have a significantly greater seed P content than seed produced on an organic farm with application of rock phosphate or with no fertilizer addition.Seed harvested from these trials were sorted into small and large seeds to provide seed with a wide range of P contents: 29–169 μg. Heavier seeds had a higher P content. Seeds were germinated and grown for three weeks in field soil in a glasshouse. Heavier seeds were more likely to have germinated after 48 h. Seedling shoot dry mass after three weeks was significantly positively influenced by seed P concentration and seed mass, that is, shoot dry mass positively correlated with seed P content. Root dry mass after three weeks also correlated positively with seed P content. However, seedling relative growth rate was not correlated with seed P content. Seed nitrogen content and concentration did not significantly influence seedling growth. The origin of the seed, that is, whether it was produced on an organic or conventional farm, the year it was harvested, and the fertilizer treatment the parent crop had received all did not significantly affect seedling growth. Enhanced early growth of seedlings may be particularly important on organic farms where herbicides are not applied and seedlings may face increased weed competition. It is suggested that organic farmers may benefit from grading out heavier seeds for sowing.

Effect of seed source and seed phosphorus content on the growth and yield of wheat in north-eastern Victoria

Summary. Wheat (Triticum aestivum L.) seed was grown at 2 locations differing in phosphorus (P) status (low and high) in north-eastern Victoria (36°S, 146°E), with applied superphosphate (kg P/ha: 0, 12, 24, 100 and 200), to produce seed of different P content. This seed was used in field and glasshouse experiments in 1993 and 1994 to investigate the effects of seed source and P content on the growth and yield of wheat. Wheat seed grown at the low P status site was smaller than seed grown at the high P status site, irrespective of the amount of applied P. Seed from the low P status site produced less early dry matter in both field and glasshouse experiments in 1993, but there was no effect of seed source on grain yield in either experiment. High seed P content either had no effect or reduced seedling emergence in the field experiments. In the glasshouse, low P content in seed from the low P status site resulted in reduced emergence. Increases in dry matter production and grain yield with higher seed P content were only observed in the drought season of 1994. Application of P resulted in increased emergence, dry matter production and grain yield at most seed P content levels but there were no significant interactions between seed P content and applied P. Application of N did not affect dry matter production in either year, but increased grain protein in both years and grain yield in 1993. Seed from low P status environments can affect early seedling growth but in average growing seasons, or in glasshouse conditions, wheat growth compensates so that differences in grain yield are not observed. However, in order to avoid risk of poor early seedling growth and possible yield penalties when the crop is stressed, wheat seed should be collected from adequate soil P status sites.

Role of mycorrhizal infection in the growth and reproduction of wild vs. cultivated plants

We tested the hypothesis that mycorrhizal infection benefits wild plants to a lesser extent than cultivated plants. This hypothesis stems from two observations: (1) mycorrhizal infection improves plant growth primarily by increasing nutrient uptake, and (2) wild plants often possess special adaptations to soil infertility which are less pronounced in modern cultivated plants. In the first experiment, wild (Avena fatua L.) and cultivated (A. sativa L.) oats were grown hydroponically at four different phosphorus levels. Wild oat was less responsive (in shoot dry weight) to increasing phosphorus availability than cultivated oat. In addition, the root: shoot ratio was much more plastic in wild oat (varying from 0.90 in the low phosphorus solution to 0.25 in the high phosphorus solution) than in cultivated oat (varying from 0.44 to 0.17). In the second experiment, mycorrhizal and non-mycorrhizal wild and cultivated oats were grown in a phosphorus-deficient soil. Mycorrhizal infection generally improved the vegetative growth of both wild and cultivated oats. However, infection significantly increased plant lifespan, number of panicles per plant, shoot phosphorus concentration, shoot phosphorus content, duration of flowering, and the mean weight of individual seeds in cultivated oat, while it had a significantly reduced effect, no effect, or a negative effect on these characters for wild oat. Poor positive responsiveness of wild oat in these characters was thus associated with what might be considered to be inherent adaptations to nutrient deficiency: high root: shoot ratio and inherently low growth rate. Infection also increased seed phosphorus content and reproductive allocation.

Effect of processing on phosphorus and phytic acid contents of some Egyptian varieties of legumes

Phytic acid and total phosphorus contents were determined in different varieties of dry legume seeds—broad beans, lentils, lupin, fenugreek, chickpea and peas. These seeds are widely used in Egypt. The dry seeds were subjected to different processing methods according to the mean of their consumption in Egypt. These processing methods include decortication, steeping, sprouting, boiling and cooking. Phytic acid and total phosphorus contents of seeds differed according to the kind, the variety and the processing method. Steeping and sprouting decreased the phytic acid content of the seeds. The phytic acid content of lupin was greatly reduced by decortication and by steeping of seeds.

Inoculation of Barley with efficient mycorrhizal fungi stimulates seed yield

Barley was inoculated in the seed bed with a mixture ofGlomus mosseae, G. fasciculatus andGigaspora margarita or with the indigenous mycorrhizal fungi and grown in 1.0m2 field plots. The introduced fungi stimulated seed yield by 27% and seed phosphorus content by 35%. A precrop with Kale had no significant effect on responses to inoculation.

Phytate and total phosphorus content of field beans (Vicia faba L.)

AbstractConsiderable variation was found in the phytate and total phosphorus contents of varieties, selections and genotypes of field beans (Vicia faba L.) The phytate phosphorus content of seeds taken from single plants of the variety Dacre indicated that large variations (1.93‐4.03 g kg−1), not significantly correlated with protein content, existed within an established variety. Although some variation in the ratio of phytate to total phosphorus was observed (0.40‐0.60), highly significant correlation coefficients were obtained for total and phytate phosphorus contents. The significance of the results obtained is discussed in relation to the potential for improving the nutritive value of field beans by breeding for lower phytate content.