Carbon-nitrogen interaction related to P,K, Ca,and Mg nutrients in field crops

Carbon (dry matter)-nitrogen relationship was expressed as DM_t = DM₀ × exp(CNI × N_t) in Gramineae crops (including root crops), and DM_t = DM₀ + CNF × N_t in Leguminosae crops, where DM_t is the amount of dry matter at various growth stages, N_t is the amount of nitrogen absorbed at various growth stages, DM₀ is the initial value, and CNI and CNI′ are coefficients. Thus, since the carbon-nitrogen relationship was different between Gramineae and Leguminosae crops, it is expected that the accumulation processes of other minerals such as phosphorus (P), potassium (K), calcium (Ca), or magnesium (Mg) during growth would be different between Gramineae and Leguminosae crops if these nutrients are closely related to the carbon and nitrogen metabolism. As nitrogen is the most important nutrient for plant growth, the relationship between N_t and the amount of other minerals such as phosphorus (P_t), potassium (K_t), calcium (Ca_t), or magnesium (Mg_t) absorbed in plants at various growth stages was examined in field crops.

In Gramineae crops, the P_t-N_t, K_t-N_t, and Mg_t-N_t relationships during growth were described as follows:

where P₀ and Mg₀ are initial values, and PNI, KNI, K_max, and MgNI are coefficients. Since the P_t-N_t and K_t-N_t relationships changed according to the growing conditions, the values of PNI and KNI were statistically estimated from the data of various growth stages at each treatment. As PNI showed a linear regression with CNI, P_t and also K_t was expressed by the equation which included CNI. Thus both phosphorus and potassium accumulation were closely related to the carbon-nitrogen interaction. While the Mg_t-N_t relationship was less affected by various growing conditions, MgNI was estimated from the data including all treatments, indicating that Mg accumulation was regulated only by nitrogen nutrient. Ca_t was not related to N_t.

In Leguminosae crops, the P_t-N_t, K_t-N_t, and Mg_t-N_t relationships were described as follows:

where P_0, K₀, and Mg₀ are initial values, and PNI′ and KNI′ are coefficients. Since the P_t-N_t, K_t-N_t, and Mg_t-N_t relationships were less affected by various growing conditions as in the case of DM_t-N_t, the values of PNI′ and KNI′, and MgNI were estimated from the data including all treatments. Thus, P, K, and Mg accumulation was closely regulated by N nutrient. Ca_t was not related to N_t.

Consequently, in Gramineae crops, P and K accumulation was assumed to be related to the carbon-nitrogen interaction, while in Leguminosae crops, P and K accumulation was assumed to be related to only nitrogen nutrient, indicating that the role of P and K nutrients differed according to differences in the balance of the carbon-nitrogen metabolism. Since MgNI was estimated from the same form of Mg_t-N_t regression regardless of Gramineae and Leguminosae crops, Mg accumulation was assumed to be closely regulated by only nitrogen nutrient. Ca accumulation was neither related to N nutrient nor carbon-nitrogen interaction.     

Difference in system of current photosynthesized carbon distribution to carbon and nitrogen compounds between rice and soybean

¹⁴CO₂ was assimilated during 10 min in leaf of rice and soybean under 21 kPa O2 (21% O₂ treatment) and 2 kPa O₂ (2% O₂ treatment) at the vegetative growth stage and flowering stage. The ¹⁴C distribution ratio to respired CO₂ and crude chemical components (sugars, polysaccharides, amino acids, organic acids, and proteins) was determined. In this paper, since emphasis was placed on the ¹⁴C distribution mechanism to carbon compounds and nitrogen compounds, the terms carbon metabolism pool (C-pool) composed of sugars and polysaccharides, and nitrogen metabolism pool (N-pool) composed of organic acids, amino acids and proteins were used. The results obtained were as follows.

¹⁴C distribution ratio to N-pool at 0 min after ¹⁴C assimilation was higher in soybean than in rice regardless of the treatments and stages, and that at 30 min after ¹⁴C assimilation under light condition markedly decreased both in rice and soybean. Therefore, especially in soybean, a large amount of photosynthesized ¹⁴C was once distributed to the N-pool, then ¹⁴C compounds in the N-pool were reconstructed into the C-pool. During this reconstruction process, ¹⁴C compounds in the N-pool were actively respired.

¹⁴C distribution to N-pool at 0 min after ¹⁴C assimilation changed slightly or did not change by the N treatment. ¹⁴C distribution to N-pool in the - N treatment of soybean (13–29 mg N g^-1 content in leaves) was higher than that in the + N treatment of rice (31–48 mg N g^-1 content in leaves). Photosynthesized carbon distribution to N-pool in rice decreased with growth, while it remained constant in soybean. Accordingly, in soybean, photosynthesized carbon was predominantly distributed to the N-pool through photorespiration and/or Calvin cycle (supplying triose-P), which was less affected by nitrogen nutrient and aging. Thus, the mechanism of photosynthesized carbon distribution to carbon and nitrogen compounds was basically regulated by inherited characters of each plant more than by the nitrogen status of leaves.

By the 2% O₂ treatment, ¹⁴C distribution to N-pool decreased in both crops regardless of N treatment, indicating that photorespiration plays an important role in the supply of the preliminarily photosynthesized carbon compounds to N-pool. In the 2% O₂ treatment, ¹⁴C distribution to N-pool was higher in soybean than in rice, indicating that triose-P transported from chloroplast was preferentially distributed to N-pool in the case of soybean.     

Efficacy of single application ammonium sulfate in suppressing potato common scab

Abstract

The objective of this study was to suppress potato common scab by lowering the soil pH and increasing the concentration of water-soluble aluminum (Al) in soil with a single application of ammonium sulfate into each row. Superphosphate (P) and potassium sulfate (K) were applied to the surface soil horizon and ammonium sulfate (N) was applied only into the rows along which potato plants were to be planted. By this application method, the soil pH was lowered and the concentration of water-soluble Al was increased in the soil of the rows where potato tubers were grown. Potato common scab was suppressed in the soil containing water-soluble Al in concentrations of 0.2 to 0.3 mg L^?1 or higher. The pH of the soil fertilized as indicated above remained lower than that of the control soil to which the mixture of N, P, and K was uniformly applied. In soil types such as Haplic Andosols containing allophane at high concentrations of 71 g kg^?1 in Memanbetsu, the suppression of potato common scab by this single application of ammonium sulfate was less effective due to the low soluble Al concentration. In other soil types, the soil pH was easily controlled and common scab was suppressed by this method. The advantages of this method are that (a) it minimizes the use of fertilizers, thus reducing the adverse effects of unnecessary fertilizers on the soil; and (b) it lowers the cost by eliminating additional agricultural chemicals and extra fertilizers.     

Effect of placement of coated urea fertilizer on root growth and rubidium uptake activity in soybean plant

Abstract

We reported in the previous paper (Takahashi et al. 1991) that the deep placement of slow release N fertilizer (coated urea) contributed to a stable increase of soybean (Glycine max L. Merr.) yield. In the previous study we observed that the deep placement of coated urea did not depress appreciably the nitrogen fixation by root nodules although fertilizer N was efficiently utilized. We assumed that the N absorbed from the roots in the deep layers did not cause nodule senescence, contributed to the maintenance of the leaf activity during the maturation stage, and that the increase in the availability of carbohydrate and N improved seed production. In the current report the effects of placement of coated urea fertilizer on the root growth and activity were studied by measuring the root dry weight and Rb absorption activity.     

Blood parameters and electrocardiogram in squeezed fish simulating the effect of net damage and recovery

ABSTRACT:   In the present study, rubber bands were tied around the girth of rainbow trout Oncorhynchus mykiss to simulate and assess the physiological damage and survival rates of fish that encounter gill nets. Physiological condition was assessed by analysis of blood lactate, pH, oxygen partial pressure and plasma potassium concentration before and after release from binding. Twenty-four hours after release, half of the test fish had died. Although the binding forces used to hamper fish did not differ significantly, blood lactate levels in the dead fish rose to 10-fold higher than those in the survivors. Consequently, the pH level fell in the group that died, whereas in the surviving group it fell only slightly and soon recovered. Potassium concentration increased after release from binding in fish that died, and the P o ₂ levels in these fish continued to drop until just before death. It was concluded that when fish get entangled in fishing nets, blood lactate accumulates because of physical fatigue and the elevated lactate levels lead to metabolic acidosis. Finally, fatal metabolic conditions could cause higher mortality rates, even in escapees.     

Effect of oil droplet sizes of oil-in-water emulsion on the taste impressions of added tastants

ABSTRACT:   By conducing organoleptic analysis, the authors investigated the effect of oil droplet size on human preference to the taste of oil-in-water (o/w) emulsions to which several tastants were added. Two singly dispersed o/w emulsions, different in oil droplet sizes, consisting of 10% triacilglycerol purified from tuna, sardine or soybean oil, 0.5% emulsifier and water were prepared by ceramic membrane filtration. Organoleptic analysis showed that the impressions of sweetness, bitterness and umami, which were developed by addition of certain taste substances, were different between o/w emulsions with different oil droplet sizes. The results of two-bottle choice tests, which were carried out using olfactory-blocked mice, showed that o/w emulsions with 1.00-µm droplets, with added sweet or bitter substances, were preferred to emulsion with 5.50-µm droplets. These results suggest that the droplet size of o/w emulsion remarkably influences certain taste impressions created by added taste substances.     

Fortification of <Emphasis Type="Italic">niboshi</Emphasis> with histidine prepared from <Emphasis Type="Italic">katsuobushi</Emphasis> protein digest

ABSTRACT:   Free and total histidine contents in the muscle of various fishes and invertebrates caught in the Seto Inland Sea were estimated. These contents were higher in the muscles from skipjack, yellowfin tuna, yellowtail and mackerel than in those from lizard fish, sea bream and hairtail. Invertebrate muscles, except squid, contained low free and total histidine. Boiled and dried anchovy ( niboshi ) contained lower free histidine than that of dried anchovy (suboshi). To prepare free histidine-rich extracts, the waste residue of soup stock from smoke-dried and shaved skipjack ( katsuobushi ) was digested with proteases. The extract of the enzyme digest contained high free histidine and was used to fortify niboshi with free histidine. If taken, the fortified niboshi may suppress food intake, and prevent obesity.     

Relationship between the Placental Retention Time and the Reproductive Performance at the Foal Heat in Thoroughbred and a Comparison with Heavy Draft

The aim of this study was to clarify the relationship between the placental retention time (PRT) and the reproductive performance following mating at the foal heat in Thoroughbreds. For this purpose, we interviewed 292 farmers over a period of 3 years with questionnaires evaluating foaling, expulsion of placenta and reproductive performance at the foal heat in 1,432 mares. The obtained data were later compared with a previous study of heavy draft mares. The average of the PRT of the 1,432 Thoroughbred mares was 58 ± 88 min (mean ± SD). The mean PRT of Thoroughbreds was significantly shorter than that of the148 min of heavy draft mares. The incidences of retained placenta (RP) occurring in the Thoroughbred mares were 5.2 and 4.0%, for over 3 and 4 hr after foaling, respectively. The incidence of RP over 4 hr was significantly lower than that of 25% in heavy draft mares. The pregnancy rate at foal heat of the mares in which PRT was less than 3 hr was 37%, and it significantly decreased to 11% for those with PRT of more than 3 hr. In the comparison of the reproductive performance between Thoroughbred and heavy draft mares, the pregnancy rate of Thoroughbreds dropped drastically to 10% when PRT exceeded 40, and in consequence, the pregnancy rate of Thoroughbreds was significantly lower than the 30% of heavy draft mares, which had a PRT of over 4 hr. In conclusion, the Thoroughbred mares had a low incidence of RP, however, a PRT exceeding 3 hr severely affected the reproductive performance at the foal heat.     

Proliferative potential of endometrial stromal cells, and endometrial and placental expression of cyclin in the bovine

The objective of the present investigation was to study proliferative activity of fibroblast-like endometrial stromal cells in bovine endometrial caruncular (CAR) and intercaruncular (ICAR) areas that have distinct functions during implantation. Endometrial stromal cells were derived from CAR and ICAR of nonpregnant cows, and their proliferative potential was analyzed in an in vitro cell culture system. In addition, expression of four types of cell cycle regulatory molecules was analyzed by RT-PCR in samples of CAR, ICAR, cotyledon (COT) and fetal membrane of both artificially inseminated (AI) and somatic nuclear transferred (NT) cows on days 30 and 60 of gestation. The proliferation growth curve showed that the cells derived from CAR had higher proliferative activity than that of ICAR-derived cells. No morphological differences were found between the cells derived from CAR and ICAR at population-doubling levels (PDL) of the two. Most of the cells derived from ICAR of nonpregnant cows exhibited expanded shape with no further proliferation at PDL 6 with a lack of cyclin E expression. Of the regulatory molecules, cyclin D1, CDK2 and CDK4 were expressed in both CAR and ICAR cells derived from both nonpregnant, and AI cows on days 30 and 60 of gestation. The expression of cyclin E in both AI and NT cows was confined to COT and fetal membrane on day 30 of gestation. Cyclin E expression on day 60 of gestation in AI cows was observed in all but ICAR areas. In marked contrast, however, cyclin E expression on day 60 of gestation in NT cows was confined to COT, suggesting that poor placentation in these cows is possibly associated with a lack of cyclin E expression. These results suggest that CAR-derived stromal cells have higher proliferative potential, which may be related to cyclin E expression during implantation.     

Synthesis and insecticidal activity of benzoheterocyclic analogues of N'-benzoyl-N-(tert-butyl)benzohydrazide: Part 1. Design of benzoheterocyclic analogues

The N'-benzoyl group of N-tert-butyl-N'-benzoyl-3,5-dimethylbenzohydrazide (1) was converted to a series of benzoheterocyclecarbonyl groups in order to investigate the potential usefulness of superimposing a hydrazine insecticide on 20-hydroxyecdysone. A series of analogues with benzodioxole, benzodioxane, benzodioxapine, indole, benzoxazole, benzoxazine or benzothiazole instead of the phenyl group of (1) were synthesized and tested for their insecticidal activity against the common cutworm (Spodoptera litura F). N-tert-Butyl-N'-(3,5-dimethylbenzoyl)-1,3-benzodioxole-5-carbohydrazide and N-tert-butyl-N'-(3,5-dimethylbenzoyl)-2,3-dihydro-1,4-benzodioxine-6-carbohydrazide showed high insecticidal activities, superior to that of (1) and equal to that of the commercial insecticide tebufenozide (RH-5992).