Characteristics of Nodulation and Nitrogen Fixation in the Improved Supernodulating Soybean (Glycine max L. Merr.) Cultivar ‘Sakukei 4’

Abstract

Supernodulating soybean lines have more than several times as many nodules as normal cultivars. They are expected to have high nitrogen-fixing ability and enhanced productivity, but their yields have been inferior to those of normal genotypes. We have recently developed a new supernodulating cultivar,‘Sakukei 4’(formerly ‘En-b0-1-2’, presently‘Kanto 100’), with improved growth and yield. The objective of the present study was to identify the characteristics of the nodulation and nitrogen-fixing ability of Sakukei 4. In pot trials, the nodule number of Sakukei 4 was 8.3 times that of a normal cultivar,‘Enrei’, and the nodule weight per plant was 2.3 to 2.8 times the value for Enrei. The acetylene reduction activity per plant in Sakukei 4 was higher than that in Enrei and conventional supernodulating genotypes, especially during the late growth stage. Compared with conventional supernodulating lines, the improved vegetative growth in shoots and roots of Sakukei 4, especially after flowering, probably enhanced its nitrogen-fixing ability per plant. We consider that its high nitrogen-fixing ability at the seed-filling stage, would help increase its yield in fields with low nitrogen fertility.     

Sweet Potato Weevil Damage,Production Constraints,and Variety Preferences in Western Tanzania: Farmers’ Perception

Sweet potato weevils (Cylas spp.) are among the most important constraints to sweet potato (Ipomoea batatas [L.] Lam.) production in most agro-ecological zones of Tanzania. Integration of farmers’ perception on sweet potato weevil damage, production constraints, and variety preferences is crucial in developing sweet potato varieties with farmer-preferred traits and weevil resistance. The aim of this study was to identify farmers’ perceptions on sweet potato weevil damage, production constraints, postharvest storage options, and criteria used to select and grow the best sweet potato varieties in western Tanzania. Surveys were conducted in four selected districts of western Tanzania (Nzega, Sikonge, Kigoma rural, and Kasulu) known for sweet potato production. Data were collected using a structured questionnaire, focus group discussions (FGDs), and transect walk involving 122 sweet potato farmers. Weevil damage was reported by 84% of the respondents to be the overriding constraint to sweet potato production. Sweet potato diseases and drought were the next production constraints, reported by 57% and 54% of the respondents, respectively. Farmers’ preferred agronomic traits of sweet potato included high yield (25% of respondents), drought tolerance (24%), and disease and pest resistance (21%). Farmers’ preferred sweet potato culinary traits in the study areas were high dry matter content (reported by 21% of the respondents), followed by reduced cooking time, taste and fiber content (each reported by 19% of the respondents). The above-mentioned production constraints and farmers’ preferred traits are useful selection criteria for improving sweet potato with respect to weevil resistance and enhanced storage-root yield and quality.     

Yielding Performance of “Kita-aoba”, High-yielding Rice Variety for Hokkaido Region,Northern Japan

Abstract

The yielding performance of the first high-yielding rice variety for Hokkaido, Kita-aoba, after application of various amounts of nitrogen (9.0 to 23.7 g m-² in 2008 and 10.5 to 16.5 g m-² in 2010) and under various planting densities (13.2 to 33.2 hills m-² in 2008 and 17.5 to 36.8 hills m-² in 2010) was examined in comparison with that of the common variety, Kirara397. Kita-aoba had higher grain yield than Kirara397 owing to its large sink capacity through larger sink capacity per unit biomass at heading. Kita-aoba had a high yield potential (the maximum grain yield of 1081 g m-²), and achieved a high grain yield even in Hokkaido where the rice-growing season is short. Kita-aoba had a large sink size, but, judging from the relationship between sink capacity and percentage of sink filled, further increase of sink size might not result in increase of grain yield. Kita-aoba showed a great increase in shoot dry matter from heading to maturity, but it was not enough to fill its large sink.     

A Comparative Study of SSR Diversity in Chinese Major Rice Varieties Planted in 1950s and in the Recent Ten Years （1995-2004）

Forty pairs of SSR markers were used to compare the genetic diversity changes in 151 Chinese major rice varieties planted in 1950s and in the recent ten years. Of 40 SSR loci, 39 were found to be polymorphic while one locus (RM479) monomorphic. A total of 213 alleles were identified from the 39 polymorphic loci. The average number of alleles per locus (Na) was of 5.5, ranging from 2 to 11. Nei’s gene diversity index (He) varied drastically among loci from 0.309 at RM174 to 0.869 at RM418, with an average value of 0.649. There existed significant difference in SSR allelic diversity between indica and japonica subspecies, and indica had more variation than japonica both in Na and He. By comparison with the genetic changes in Na and He, it was revealed that the varieties planted in 1950s had more alleles and higher He than those in the recent ten years both for indica and japonica rices. The difference between two subspecies for Na was significant in a tendency over time (indica: z = 2.677, P = 0.007; japonica: z = 3.441, P = 0.001), but not significant for He (indica: z = 1.471, P = 0.141; japonica: z = 1.932, P = 0.053). Analysis of molecular variance (AMOVA) indicated that there existed significant difference (P < 0.05) in genetic variation between the two periods, of which more genetic variation was contributed by indica (Fst = 0.050) and japonica (Fst = 0.082) subsets. Using locus-by-locus AMOVA procedure, significant genetic differentiations were observed in 13 loci (RM21, RM128, RM147, RM169, RM190, RM221, RM231, RM251, RM253, RM317, RM341, RM418, and RM478) for indica varieties and 11 loci (RM101, RM135, RM152, RM159, RM169, RM190, RM251, RM253, RM311, RM418, and RM478) for japonica ones between the two periods. It was found some alleles had been lost in current major rice varieties as comparing with those in 1950s. Therefore, it should be necessary to exploit more alien elite genetic resources for extension of genetic background in current rice breeding program.     

Cadmium Accumulation and Its Toxicity in Brittle Culm 1 （bcl）, a Fragile Rice Mutant

Cadmium （Cd） accumulation and toxicity in rice plants were characterized and identified by using brittle culm 1 （bcl）, a fragile rice mutant and its wild type （Shuangkezao, an indica rice） as materials by hydroponics. The low Cd level didn＇t obviously affect the growth parameters in both rice genotypes, but under high Cd levels （1.0 and 5.0 μmol/L）, the growth of both rice plants were substantially inhibited. Moreover, bcl tended to suffer more seriously from Cd toxicity than Shuangkezao. Cd accumulation in both rice plants increased with the increase of Cd levels. There was a significant difference in Cd accumulation between the two rice genotypes with constantly higher Cd concentration in bcl, which also accumulated more Cd at 0, 0.1, and 1.0 μmol/L Cd levels. The same case was found in the two rice plants grown on Cd-contaminated soil. This suggested that cell wall might play an important role in Cd accumulation in rice plants by the physiological mechanisms. The malondialdehyde （MDA） content, superoxide dismutase （SOD） and peroxidase （POD） activities in rice plants were affected differently under Cd treatments, and which implied that POD might play the main role in detoxifying active oxygen free radical. A significant difference in antioxidative system between the two rice genotypes was found with constantly higher MDA content, SOD and POD activities in bcl. In summary, bcl accumulated more Cd and appeared to be more sensitive to Cd stress compared with its wild type.     

Properties of Starch and Protein of “Hattan-Type Varieties” of Rice Suitable for Brewing Original Hiroshima Sake

Abstract

By successive crossing using Hattan-type varieties originating from “Hattanso” as a parent, “Hattan-type varieties” of rice suitable for brewing the original Hiroshima sake have been bred. In this study, the difference in the properties of starch and protein among the Hattan-type varieties was examined. Six Hattan-type varieties, Hattanso, Hattan No.10, Hattan No.35, Hattan No.40, Hattan-nishiki No.1 and Hattan-nishiki No.2, were used. As the properties of starch, amylose content, pasting properties and gelatinization properties were examined. The pasting and gelatinization properties were examined using a rapid viscoanalyzer (RVA) and a differential scanning calorimetry (DSC), respectively. As the properties of protein, the compositional ratio of two types of protein bodies (PB-II/PB-I) was analyzed. However, no significant differences in the above properties were observed among these Hattan-type varieties. The above properties of starch and protein in Hattanso seem to be retained in all of these varieties. In these varieties, breeding might not have been aimed at improvement of the properties of starch and protein.     

Effects of Seeding Rate and Nitrogen Application Rate on Grain Yield and Protein Content of the Bread Wheat Cultivar ‘Minaminokaori’ in Southwestern Japan

Abstract

We examined the effects of seeding rate, 50 or 150 seeds m-², nitrogen (N) application rate at active tillering and jointing, 4 and 2 g N m-², respectively, or none, and N application rate at anthesis, 0, 2, 4, or 6 g N m-², on grain yield and protein content of a bread wheat cultivar, ‘Minaminokaori’, during the 2004–2005 crop season in southwestern Japan. Grain yield was similar at a seeding rate of 50 and 150 seeds m-². It was higher when 4 and 2 g N m-² were applied at active tillering and jointing, respectively (4–2N), than when no N was applied at these stages (0–0N). However, it was not influenced by N application rate at anthesis. Grain protein content was similar at 50 and 150 seeds m-². It was higher in 4–2N than in 0–0N. It was the highest when 6 g N m-² was applied at anthesis, followed by 4, 2, and 0 g N m-². The SPAD value at anthesis was higher at 50 than 150 seeds m-², but leaf area index (LAI) at anthesis was similar at 50 and 150 seeds m-² and protein content of grain was nearly the same at 50 and 150 seeds m-² irrespective of N application rate at anthesis. LAI and the SPAD value were higher in 4–2N than in 0–0N and the protein content of grain was also higher in 4–2N than in 0–0N irrespective of N application rate at anthesis. Therefore, both LAI and the SPAD value may be important traits related to the N application rate at anthesis suitable for yielding wheat grain with a high protein content.     

Yield losses in potatoes,onions and rutabagas in Southwestern Ontario,Canada—the case for pest control

Yield losses in potatoes, onions and rutabagas due to insects, weeds and diseases were measured. In the absence of any pest control, average losses of 64% for potatoes on mineral soil, 85% for potatoes on organic soil, 100% for onions and 88% for rutabagas were recorded. Major single causes of loss were: potato leafhopper, Empoasca fabae (Harris) for potatoes on mineral and organic soil; weeds and early blight, Alternaria solani (Ell. & Mart.) for potatoes on organic soil; weeds, onion maggot, Delia antiqua (Meigen) and leaf blight, Botrytis squamosa (J. C. Walker) for onions; cabbage maggot, Delia radicum (Linnaeus) and weeds for rutabagas. The monetary losses experienced and the cost of each pesticide programme were calculated.     

The Marine-Derived Sipholenol A-4-O-3′,4′-Dichlorobenzoate Inhibits Breast Cancer Growth and Motility in Vitro and in Vivo through the Suppression of Brk and FAK Signaling

Sipholenol A is a natural sipholane triterpenoid isolated from the Red Sea sponge, Callyspongia siphonella. Previous studies showed the antimigratory and antiproliferative activities of the semisynthetic sipholenol A esters against breast cancer cell lines. This study investigated the effects of sipholenol A-4-O-3′,4′-dichlorobenzoate (SPA) on the growth, migration and invasion of diverse human breast cancer cells. Results showed that SPA inhibited the growth of the human breast cancer cells, MDA-MB-231, MCF-7, BT-474 and T-47D, in a dose-dependent manner. Immunofluorescent analysis showed that SPA significantly reduced Ki-67-positive cells in MDA-MB-231 cells. Flow cytometry and Western blot analyses revealed that SPA treatment suppressed MDA-MB-231 cell growth by inducing cell cycle arrest at the G1 phase. In addition, SPA suppressed breast cancer cell migration, invasion and decreased Brk and FAK activation in a dose-dependent manner. Molecular docking study suggested a perfect fitting at the FAK’s FERM domain, inhibiting the main autophosphorylation site, Y397, which was further confirmed by Western blot analysis. Most known small molecule FAK inhibitors target the kinase domain, creating several off-target side effects. The in vivo studies showed that SPA treatment suppressed breast tumor growth and Ki-67, CD31, p-Brk and p-FAK expression in orthotopic breast cancer in nude mice. In conclusion, SPA inhibited the growth, invasion and migration of breast cancer cells possibly via deactivating Brk and FAK signaling, suggesting good potential for therapeutic use to control invasive breast cancer.     

Verification and evaluation of the “Three Optimums Theory”in rice breeding for maximum yield

Rice breeding for maximum yield is a hot topic today in the rice community of the world, and a hard nut to crack into the bargain. For many years, we have been devoted to the subject. In 1987 we discussed the subject in publications at home and abroad, in which we first introduced the general strategy of combining ideal plant morphology with the use of vigor. Afterward, drawing on the wisdoms of other researchers, we experimented with test materials featuring "rather short stalks" and "rather big panicles", but the results were not very satisfactory. Then, we switched from the "two rathers" to the "three optimums" (plant height, panicle size, and tillering ability). Three years' (1991-1993) verification, especially the demonstra     

Cloning and Bioinformatical Analysis of Phospholipase Dα1 Gene and Its Promoter in the Latex of Rubber Tree (Hevea brasiliensis Muell.Arg.)

植物磷脂酶PLDα1与伤害信号转导密切相关,是伤害诱导内源茉莉酸(Jasmonic acid,JA)生物合成的关键酶之一.橡胶树胶乳PLDα1基因(HbPLDα1)表达的研究将有助于揭示橡胶树乳管细胞JA信号转导及其调控橡胶生物合成的机制.在EST序列的基础上,通过RACE和Genome Walking方法分别克隆了橡胶树胶乳的HbPLDα1基因及其启动子序列.HbPLDα1基因的cDNA全长为2 870 bp,包含长度为2427 bp的完整开放阅读框(ORF),具有典型的植物PLDα蛋白保守功能域,与同属大戟科的蓖麻和麻风树的PLDα1基因亲缘关系最近.HbPLDα1基因启动子区域长为1 559 bp,除含有TATA box和CAAT box等基本顺式作用元件外,还存在JA和脱落酸等激素响应元件以及干旱胁迫等环境信号响应元件,这表明HbPLDα1基因的表达可能受激素和环境信号的调控,在橡胶树乳管细胞对激素和环境信号的响应过程中发挥重要作用.