Assessing the acceptance of the system of rice intensification among farmers in rainfed lowland rice region of Cambodia

We conducted interview survey with rainfed rice farmers at a commune in southern Cambodia to identify the determinants of their adoption or rejection of the system of rice intensification (SRI) for the wet season of 2014. SRI was first introduced to the commune in 2003 and spread among the farmers, but the number of farmers discontinuing the practice has increased since 2011. We classified the farmers into four categories: those who practice SRI in all their fields (OA), farmers who practice SRI in some of their fields (PA), farmers who had practiced SRI but discontinued it (DA), and farmers who have never practiced SRI (CR). Farmers in different categories of SRI adoption differed in their access to water sources. The majority of OA and PA farmers had supplementary water sources, which was, however, available to less than 50% of DA farmers and only 15% of CR farmers. Both PA and DA farmers mentioned water shortage as the reason for not practicing SRI in some (PA) or any (DA) of their fields, but they differed in the number of rice fields. All the PA farmers had more than one field, whereas a majority of DA farmers had only one field. Labor shortage and difficulty of planting in a regular grid pattern were also mentioned as the reason for not practicing SRI by the farmers, particularly by DA farmers. Water constraint and difficulties in transplanting were thus identified as two major determinants of SRI adoption/rejection at the study site.     

Segregation of leptines and other glycoalkaloids inSolanum tuberosum (4x) ×S. chacoense (4x) crosses

A clone, 8380-1, selected fromSolanum chacoense (PI 458310) for its high foliage content of the leptine glycoalkaloids, a factor in resistance to Colorado potato beetle, was doubled in chromosome number from 2n=2x=24 to 2n=4x=48. Three 4x clones were crossed with sixS. tuberosum (4x) clones. Foliage glycoalkaloid contents were measured for 452 F1 hybrids from 15 crosses. The 4xchacoense parental clones were not different in respect to glycoalkaloid contents and were similar to the original 2x clone. All F1 hybrids synthesized foliage leptines ranging from 9 to 369 mg/100 g fresh weight (fw) with a mean content of 113 mg/100 g fw. The proportion of leptines in the total glycoalkaloid content ranged from 1% to 62% with a mean of 25%. The 4xchacoense parent mean leptine content was 1482 mg/ 100 g fw which was 90% of the total glycoalkaloid content. Tubers from 136 hybrids and the threechacoense parental clones were tested for glycoalkaloid contents. The tuber solanine + chaconine contents of the 136 hybrids ranged from 30 to 180 mg/100 g fw with a mean of 79. The mean tuber content of the threechacoense parental clones was 157 mg/100 g fw. Leptines were not found in any of the tubers.     

Amphidinolide C2, New Macrolide from Marine Dinoflagellate Amphidinium Species

A new cytotoxic 25-membered macrolide, amphidinolide C2 (1), has been isolated from marine dinoflagellate Amphidinium sp. (Y-71 strain), and the structure 1 was elucidated on the basis of spectroscopic data and chemical means.     

Effect of boiled barley-rice-feeding in hypercholesterolemic and normolipemic subjects

Barley contains approximately 10% dietary fiber and is easily cooked with rice, the dominant cereal in Japan, to increase the intake of dietary fiber. This research involved three experiments to examine the influence of barley on blood lipids in human subjects. All subjects received a boiled barley-rice (50/50 w/w mix) supplement two times per day in place of rice for 2 or 4 weeks. In the normolipemic subjects, serum lipids were unaffected by the ingestion of barley for 4 weeks. In twenty hypercholesterolemic men aged 41 ± 5 years, the ingestion of barley was associated with a significant fall in serum total cholesterol, LDL-cholesterol, phospholipids and LDL and VLDL-lipoproteins. In seven mildly hypercholesterolemic women aged 56±7 years, a significant improvement of serum lipid profiles was observed. The present study suggests the possibility that the ingestion of barley-rice could lower serum lipids in hypercholesterolemic subjects.     

Characterization of an Alginate Lyase,FlAlyA, from Flavobacterium sp. Strain UMI-01 and Its Expression in Escherichia coli

A major alginate lyase, FlAlyA, was purified from the periplasmic fraction of an alginate-assimilating bacterium, Flavobacterium sp. strain UMI-01. FlAlyA showed a single band of ~30 kDa on SDS-PAGE and exhibited the optimal temperature and pH at 55 °C and pH 7.7, respectively. Analyses for substrate preference and reaction products indicated that FlAlyA was an endolytic poly(mannuronate) lyase (EC 4.2.2.3). A gene fragment encoding the amino-acid sequence of 288 residues for FlAlyA was amplified by inverse PCR. The N-terminal region of 21 residues except for the initiation Met in the deduced sequence was predicted as the signal peptide and the following region of six residues was regarded as propeptide, while the C-terminal region of 260 residues was regarded as the polysaccharide-lyase-family-7-type catalytic domain. The entire coding region for FlAlyA was subjected to the pCold I—Escherichia coli BL21(DE3) expression system and ~eight times higher yield of recombinant FlAlyA (recFlAlyA) than that of native FlAlyA was achieved. The recFlAlyA recovered in the periplasmic fraction of E. coli had lost the signal peptide region along with the N-terminal 3 residues of propeptide region. This suggested that the signal peptide of FlAlyA could function in part in E. coli.     

Increase in Iron and Zinc Concentrations in Rice Grains Via the Introduction of Barley Genes Involved in Phytosiderophore Synthesis

Increasing the iron (Fe) and zinc (Zn) concentrations of staple foods, such as rice, could solve Fe and Zn deficiencies, which are two of the most serious nutritional problems affecting humans. Mugineic acid family phytosiderophores (MAs) play a very important role in the uptake of Fe from the soil and Fe transport within the plant in graminaceous plants. To explore the possibility of MAs increasing the Fe concentration in grains, we cultivated three transgenic rice lines possessing barley genome fragments containing genes for MAs synthesis (i.e., HvNAS1, HvNAS1, and HvNAAT-A and HvNAAT-B or IDS3) in a paddy field with Andosol soils. Polished rice seeds with IDS3 inserts had up to 1.40 and 1.35 times higher Fe and Zn concentrations, respectively, compared to non-transgenic rice seeds. Enhanced MAs production due to the introduced barley genes is suggested to be effective for increasing Fe and Zn concentrations in rice grains.     

Breeding efforts to mitigate damage by heat stress to spikelet sterility and grain quality

Global warming is predicted to aggravate the risk of unstable crop production. It is of great concern that damage to rice spikelet sterility and grain quality will increase, resulting in yield and economic losses. To secure the global food supply and farmers’ income, the development of rice cultivars with heat resilience is a pressing concern. Regarding spikelet sterility, rice cultivars with heat tolerance at different growth stages have been identified in recent years. The early-morning flowering (EMF) trait is effective in heat escape because it shifts the time of day of flowering to earlier in the morning when it is cooler. Although varietal differences are very small, there are some genetic resources for EMF in wild rice accessions. Regarding heat-induced grain chalkiness, heat-tolerant japonica cultivars for mitigating white-back type of chalky grains (WBCG) were found. Quantitative trait loci for heat tolerance at flowering, EMF, and for WBCG in grain quality have been mapped on the rice chromosomes. Further genetic efforts have been successfully connected to the development of near-isogenic lines for each trait with tagged molecular markers. These breeding materials are quite unique and useful in facilitating marker-assisted breeding toward the development of heat-resilient rice in terms of spikelet sterility and grain quality.     

Paraticulate metals in waters of a typical irrigation river: The River Sakuragawa,Japan

The particulate metallic elements in waters of a water system of the River Sakuragawa and Lake Kasumigaura were measured by the multielement analyses using particle-induced X-ray emission. The heavy metal particulates for environmental standards were less than 0.0001 ppm for Cd, 0.00037 ppm for Cr, and 0.00078 ppm both for Hg and Pb in the river waters. The predominant metal particles in the waters were Fe, Mn, and Zn.     

Subaru telescope observations of Deep Impact

The impact cratering process on a comet is controversial but holds the key for interpreting observations of the Deep Impact collision with comet 9P/Tempel 1. Mid-infrared data from the Cooled Mid-Infrared Camera and Spectrometer (COMICS) of the Subaru Telescope indicate that the large-scale dust plume ejected by the impact contained a large mass (approximately 10(6) kilograms) of dust and formed two wings approximately +/-45 degrees from the symmetric center, both consistent with gravity as the primary control on the impact and its immediate aftermath. The dust distribution in the inner part of the plume, however, is inconsistent with a pure gravity control and implies that evaporation and expansion of volatiles accelerated dust.     

A 49-kilodalton phosphoprotein in the Drosophila photoreceptor is an arrestin homolog

The gene encoding the 49-kilodalton protein that undergoes light-induced phosphorylation in the Drosophila photoreceptor has been isolated and characterized. The encoded protein has 401 amino acid residues and a molecular mass of 44,972 daltons, and it shares approximately 42 percent amino acid sequence identity with arrestin (S-antigen), which has been proposed to quench the light-induced cascade of guanosine 3',5'-monophosphate hydrolysis in vertebrate photoreceptors. Unlike the 49-kilodalton protein, however, arrestin, which appears to bind to phosphorylated rhodopsin, has not itself been reported to undergo phosphorylation. In vitro, Ca2+ was the only agent found that would stimulate the phosphorylation of the 49-kilodalton protein. The phosphorylation of this arrestin-like protein in vivo may therefore be triggered by a Ca2+ signal that is likely to be regulated by light-activated phosphoinositide-specific phospholipase C.