Feeding cashew nut shell liquid decreases methane production from feces by altering fecal bacterial and archaeal communities in Thai local ruminants

The effect of feeding cashew nut shell liquid (CNSL) on fecal fermentation products and microbiota was investigated in Thai native cattle and swamp buffaloes. Four of each animal were fed rice straw and concentrate diet with control pellets without CNSL for 4 weeks, followed by the same diet with pellets containing CNSL for another 4 weeks, so that CNSL was administered at a level of 4 g/100 kg body weight. Feces were collected the last 2 days in each feeding period. CNSL alkyl phenols were recovered from feces (16%–28%) in a similar proportion to those in the diet, indicating that most functional anacardic acid was not selectively removed throughout the digestive tract. In vitro production of gas from feces, particularly methane, decreased with CNSL feeding. The proportion of acetate in feces decreased with CNSL feeding, whereas that of propionate increased, without affecting total short-chain fatty acid concentration. CNSL feeding changed fecal microbial community, particularly in swamp buffaloes, which exhibited decreases in the frequencies of Treponema, unclassified Ruminococcaceae, and Methanomassiliicoccaceae. These results suggest that CNSL feeding alters not only rumen fermentation but also hindgut fermentation via modulation of the microbial community, thereby potentially attenuating methane emission from the feces of ruminant animals.     

Gibberellic acid (GA3) induced changes in proanthocyanidins and malt quality of two and six-row husked barleys

Analysis of husked barleys for proanthocyanidins and malt qualityattributes has shown that not a single variety is free ofproanthocyanidins. The proanthocyanidins in barley grains variedfrom 3.85 to 4.94 mg/g as catechin equivalent. The concentrationof proanthocyanidins decreased, while total soluble sugars, reducingsugars, diastatic power and -amylase activity increasedduring maltings as well as with exogenous gibberellic acid (GA₃)application. Alfa 93 (two-row) and RD2560 (six-row) varietiesappeared to be superior for malting and brewing purposes on thebasis of proanthocyanidins, total phenols, diastatic power and-amylase activity. It is suggested that exogenous applicationof GA₃ at 15 ppm may be useful for producing good quality maltfrom barley grains.     

Nematicides induced changes in the chemical constituents of potato tubers

Changes in the chemical constituents of potato tubers grown under different concentrations of 3 synthetic organic nematicides (carbofuran, aldicarb and phorate) and a natural plant product (sawdust) were investigated. There were no significant differences in the specific gravity, dry matter and starch content of tubers from different treatments. A significant increase in the content of non-reducing and total sugars was observed in all the treatments. Nematicidal treatments had significant effects on reducing sugars, true protein, free amino acids, orthodihydroxy phenols, beta-carotene and ascorbic acid. Application of nematicides reduced the content of total phenolic compounds which is a desirable change from a processing viewpoint. Potatoes grown under different nematicidal treatments can be processed into chips and French fries as they contain permissible levels of reducing sugars required for these forms of processing.     

变黄环境对烤烟总酚含量变化规律的影响

试验采用206最优回归设计方案，研究了不同烘烤变黄温、湿度对烤烟中部叶总酚含量的变化规律。结果表明：在试验温湿度范围内，随着温度的升高，总酚含量呈现先升后降的变化趋势，湿度对总酚的影响则与温度相反，温度对总酚含量的影响大于湿度，中温及高湿更有利于总酚含量的增加。综合考虑，以提高总酚含量从而增加烟叶中香气值，建议变黄环境在温度35．8—36．7℃、相对湿度93．0％-95．0％（即干湿差2．0℃）这宜。     

Indicators of resistance of sunflower plant to basal stalk rot (Sclerotinia sclerotiorum): Symptomatological,biochemical, anatomical,and morphological characters of the host

Summary The object of this work was a study of the relationship between the field reactions of different sunflower genotypes to basal stalk rot (in terms of severe (dead plants) and incipient wilting, and lesion length) and some biochemical (phenol concentration), morphological (plant height, and stem and flower-bud diameters) and anatomical (xylem and cortical indexes) characters of the host. Plants from 8 inbred lines at closed flower-bud stage were artificially inoculated with mycelium at the base of the stem. The percentage of dead plants for each inbred line and the lesion length and wilting range for individual plants after 7 days were recorded.A positive and highly significant correlation coefficient between the percentage of dead plants and lesion length was found for the three years of the study (r=0.83; P<0.01). A highly significant association between lesion length and wilting range for individual plants was always found (P=0.00). Postinfectional phenol content exhibited a strong negative correlation with lesion length and the percentage of dead plants in all the experiments (P=0.05). Association between postinfectional phenol content and wilting range for individual plants was significant for all the years studied (P<0.05). No correlation between phenol levels in healthy plants of the different sunflower genotypes and their susceptibility was found. Morphological characters positively correlated with lesion length but only plant height exhibited significant values for the three years. Associations between wilting range and morphological characters for individual plants were significant for one of the two years analyzed (P<0.05). Xylem index showed a negative correlation with lesion length which was significant one of the two years studied.The lesion length measure seems to be a simple and direct method for resistance screening before the flowering period. Although strong relations with postinfectional phenol levels were found, their determinations would be too much time consuming and not completely reliable. The relationships between other characters measured and disease resistance would indicate that physiological mechanisms could be related to resistance.     

The inheritance and biochemistry of resistance to Sclerotinia sclerotiorum leaf infections in sunflower (Helianthus annuus L.)

Summary Resistance of sunflower leaves to attack by Sclerotinia sclerotiorum was studied by infecting them, in the field, with agar disks containing Sclerotinia mycelium. Resistance levels were determined by the length of lesions after a given period. There were significant differences in reaction between both sunflower hybrids and inbred lines. Different Sclerotinia isolates gave the same classification of sunflower genotypes. The results of trials repeated in one year or different years were significantly correlated. The general combining ability variance/specific combining ability variance ratio was 1.35. Strict sense heritability was 0.61±0.03. The midparent-offspring correlation coefficient was significant, but the relation between per se values of the male parents used with the values of their hybrids was much closer than that for the female parents. Mean heterosis for resistance was 28.9%, compared with the midparent. The results of the leaf resistance test are frequently correlated with levels of resistance to root attack by Sclerotinia. Possible use of this test in breeding both directly for leaf resistance and indirectly for root resistance are discussed. H.P.L. Chromatography studies of the phenols present in healthy and infected leaves distinguished 19 compounds, all of the inhibitin type. There was a large increase in phenol content in leaves infected by Sclerotinia, for all genotypes. However, more especially in uninfected leaves, the contents of 3 chromatogram peaks, numbered 4, 6 and 9, showed a close relation with levels of Sclerotinia resistance. It is proposed that these compounds could be used as markers of certain types of resistance.     

Investigations on possible mechanisms of resistance to nematodes in Musa

Summary The burrowing nematode (Radopholus similis) is one of the major nematode species attacking banana and plantains. Sources of resistance to this nematode were found and studies were made of the resistance mechanisms involved. Relatively greater numbers of preformed phenolic cells were found in roots of the resistant and intermediately resistant cultivars Yangambi km5 and Gros Michel than others. However, in another resistant cultivar, Pisang Jari Buaya, fewer phenolic cells were found, but this clone had high numbers of cells with lignified walls suggesting a different mechanism of resistance. An interesting correlation was found between level of susceptibility to R. similis and root dry matter. A possible role of lignin in resistance to R. similis in Musa is also indicated.     

Foliar Application of Benzothiadiazole and Salicylic Acid to Combat Sheath Blight Disease of Rice

A field study was undertaken to ascertain the effects of elicitors viz. benzothiadiazole (BTH) and salicylic acid (SA) on defense related enzymes viz. peroxidase, phenylalanine ammonia lyase, superoxide dismutase, chitinase and β-1,3-glucanase, and phenols in rice (Pusa Basmati I) plants. First foliar spray of BTH (50 mg/kg) and SA (50 mg/kg) was done at the maximum tillering stage and inoculation with Rhizoctonia solani was carried 24 h after elicitor treatment. Elicitors were further sprayed at every growth stage. Time course analysis showed peak accumulation of defense related enzymes and phenols in the rice leaves treated with BTH and SA, and accumulation was the highest at the flowering stage. Higher enzymatic activity was observed in elicitor treated plants inoculated with R. solani. Compared to the untreated control plants, application of elicitors before R. solani inoculation significantly elicited the defense related enzymes and phenols. Moreover, application of elicitors had a positive effect on yield and disease reduction. It is suggested that pretreatment of rice leaves with BTH and SA could be used to enhance the level of protection against sheath blight and to improve rice yield in the fields.     

药食植物鱼腥草对亚硝化反应抑制作用的研究

在固液比1∶10,提取温度80℃,提取时间60 min条件下,研究五种溶剂提取鱼腥草活性物质中的总黄酮和总酚含量及其对亚硝胺合成的阻断作用与对亚硝酸钠的清除效果。结果表明,55%丙酮提取鱼腥草活性物质中的总黄酮和总酚含量最高,对亚硝胺合成的阻断作用与对亚硝酸钠的清除效果最好,其最佳浓度下提取的鱼腥草活性物质对亚硝胺合成的阻断率达92.81%,对亚硝酸钠的清除率达89.53%;当提取物中的总黄酮含量和VC溶液浓度均为2 mg/mL时,二者对亚硝胺的阻断率分别为51.08%和66.91%,对亚硝酸钠的清除率分别为23.04%和38.22%。     

Plant lignin and nitrogen contents control carbon dioxide production and nitrogen mineralization in soils incubated with Bt and non-Bt corn residues

Bt (Bacillus thuringiensis) corn is reported to produce lignin-rich residues, compared to non-Bt (NBt) corn, suggesting it is more resistant to decomposition. As the Bt gene is expressed selectively in stem and leaf tissue, it could affect lignin distribution in corn, which naturally has greater lignin content in roots than in stems and leaves. Our objective was to evaluate the effects of corn plant components, the Bt gene and elevated-lignin inputs on decomposition. Roots, stems and leaves from Bt corn and NBt corn isolines enriched with ¹³C and ¹⁵N were finely ground and mixed separately with soil, then incubated at 20 °C for 36 weeks. The effect of elevated lignin on decomposition was tested by adding a commercial lignin source (indulin lignin) to half of the samples. In addition to weekly CO₂ analysis and regular measurement of N mineralization, the degree of lignin degradation was evaluated at 1 and 36 weeks from the acid to aldehyde ratio (Ad/Al) of vanillyl and syringyl lignin-derived phenols. The CO₂ production and N mineralization was lower in root-amended soils than stem- and leaf-amended soils. The Bt genetic modification increased CO₂ production from stem-amended soils (P < 0.05) and decreased N mineralization in root-amended soils. The ¹³C and ¹⁵N results also showed more residue-C and -N retained in soils mixed with NBt stem residues. After 36 weeks leaf- and stem-amended soils with indulin lignin had a lower Ad/Al ratio and were less degraded than soils without exogenous lignin. In conclusion, plant lignin and nitrogen contents were good predictors of CO₂ production and N mineralization potential. Corn roots decomposed more slowly than aboveground components emphasizing the importance of recalcitrant root residues in sustaining the organic matter content of soil.