Dynamics of Abscisic Acid Levels during Grain-Filling in Rice : Comparisons between Superior and Inferior Spikelets

Abstract

In a rice panicle, the superior spikelets display higher growth rates than the inferior spikelets during the initial phase of grain-filling. To better understand the regulatory mechanism of this phenomenon, we examined the dynamics of endogenous abscisic-acid (ABA) levels and the effects of shading on the dynamics during the grain-filling period in superior and inferior spikelets. While ABA content in the superior spikelets increased rapidly after flowering, that in the inferior spikelets increased slowly and reached the maximum later than in the superior spikelets. Shading significantly exaggerated the inherently different ABA dynamics between the superior and inferior spikelets. We concluded that ABA levels are correlated with the dry matter accumulation patterns of spikelets. These results support our hypothesis that ABA is involved in assimilate partitioning among spikelets in a panicle during the initial phase of grain-filling of rice.     

Characterization of the nutritive value of tropical legume grains as alternative ingredients for small‐scale pork producers using in vitro enzymatic hydrolysis and fermentation*

In the tropic, the small‐scale pork production is negatively influenced by the low availability of high protein ingredients. The study aimed to compare the protein and starch hydrolysis as well as fibre fermentation of five tropical legume grains (Canavalia brasiliensis, CB; Lablab purpureus, LP; Vigna unguiculata, white WVU; pink PVU and red RVU) and a control (extruded full‐fat soybean (SB)), using an in vitro model that simulated digestion in the gastrointestinal tract of pigs. A sequential in vitro hydrolysis was carried out with pepsin (120 min) and pancreatin (240 min) to determine the degree of hydrolysis (DH) of protein and starch. The indigestible residue was fermented in vitro with pig faecal inoculum to compare the modelled kinetics of gas production over 72 h and the production of short‐chain fatty acids (SCFA). After 360 min of pepsin–pancreatin hydrolysis, SB and WVU had the highest protein hydrolysis (76% and 66%) and PVU and WVU the highest starch hydrolysis (70% and 64%) (p < 0.01). The in vitro fermentation of the indigestible residue of WVU resulted in the highest (482 ml/g DM; p < 0.001) and CB the lowest (335 ml/g DM) gas production. These data were consistent with the SCFA production. Butyrate, propionate and total SCFA were higher (or tended) for RVU and WVU when compared with CB and SB (p = 0.015–0.085). In conclusion, the high DH of protein and starch as well as the high gas and SCFA production obtained with raw WVU makes it an interesting alternative to SB as a feedstuff for swine nutrition in the tropic. Other legume grains (LP and CB) cannot be used by pigs in their raw form.     

Effects of distillers dried grains with solubles and mineral sources on gaseous emissions

Distillers dried grains with solubles (DDGS), an important ethanol industry co-product, has been used as a high-protein feed in poultry production. Limited studies exist on their effect on air emissions, however. In the current study, 4 diets (2 × 2 factorial design: 0 or 20% DDGS + inorganic or organic mineral sources) were fed to Hy-line W36 hens from 50 to 53 wk of age and the effects of DDGS level and mineral sources on air emissions were monitored continuously for a 23-d period in environmentally controlled chambers. The NH₃, H₂ S, CH₄, nonmethane hydrocarbons, N₂ O, CO₂, and CO₂-equivalent emissions ranged from 0.51 to 0.64 g/day-hen, 0.71 to 0.84 mg/day-hen, 33.9 to 46.0 mg/day-hen, 54.1 to 60.0 mg/day-hen, 66.0 g to 72.2 g/day-hen, and 83.1 to 92.1 g/day-hen, respectively. Feeding DDGS to laying hens resulted in 14% decreased NH₃ emissions but a 19% increase in CH₄ emissions without affecting other gaseous emissions. More than 30% of N, 80% of P, 80% of K, and 50% of Ca was retained in the manure. In conclusion, feeding laying hens a diet containing 20% DDGS may be beneficial for the environment. Substitution for organic trace minerals did not affect hen performance or air emissions.     

日粮添加干玉米酒糟对泌乳奶牛干物质采食量、泌乳性能和瘤胃发酵的影响

文章旨在研究日粮中添加不同比例的干玉米酒糟对泌乳奶牛干物质采食量、泌乳性能和瘤胃发酵的影响。试验选择45头健康的中国荷斯坦奶牛,按照胎次、泌乳天数和产奶量进行区组设计,随机分配到3个处理组中,每组15头牛。对照组奶牛饲喂以玉米和豆粕为基础的日粮,不含有干玉米酒糟,试验1组和试验2组奶牛饲喂的日粮均以干玉米酒糟替代部分玉米和豆粕,替代比例分别为10%和20%(干物质基础)。预试期为2周,正试期为10周。试验结果表明,日粮添加干玉米酒糟显著提高了泌乳奶牛干物质采食量(P<0.05),而不同干玉米酒糟添加比例对奶牛的干物质采食量无显著影响(P>0.05)。日粮添加干玉米酒糟显著提高了泌乳奶牛的产奶量,且呈剂量依赖效应(P<0.05)。日粮添加干玉米酒糟对乳成分无显著影响(P>0.05),但由于产奶量的增加显著增加了乳中营养成分含量(P<0.05)。日粮添加干玉米酒糟改变了瘤胃发酵模式,降低了瘤胃液乙酸摩尔比值(P<0.05),增加了丙酸和丁酸摩尔比值(P<0.05),降低了瘤胃液NH3-N浓度。因此,可以使用干玉米酒糟替代部分玉米和豆粕来配合奶牛日粮,本试验中以20%的添加量较为合适。     

水稻生育后期谷粒真菌区系霉变损失及其防治的研究

在成都和重庆两地区,定点定期对水稻生育后期稻谷上的真菌进行分离,获得若干菌株,分属于１８个属,其中镰孢霉属（Ｆｕｒｓａｒｉｕｍｓｐｐ．）、青霉属（Ｐｅｎｉｃｉｌｕｍｓｐｐ．）、喙枝霉属（Ｒｈｉｎｏｃｌｄｉｃｌａｓｐｐ．）、交链孢霉属（Ａｌｔｅｒｎａｒｉａｓｐｐ．）、黑孢霉属（Ｎｉｇｒｏｓｐｏｒａｓｐｐ．）中的真菌为优势菌种,喙枝霉菌、棘壳孢霉菌（Ｐｙｒｅｎｏｃｈａｅｔａｓｐｐ．）、头孢霉菌（Ｃｅｐｈａｌｏｓｐｏｒｉｕｍｓｐｐ．）等水稻谷粒腐生菌尚未见报道。系统调查研究表明,同一地区水稻品种间,真菌群落的分布没有差异,但在不同的地区,水稻品种间的真菌种类及数量有所差别。通过种子处理和生育期的药剂防治,可减轻霉变对稻谷的危害,尤其以温汤浸种效果最佳。     

配合饲料中添加玉米DDGS对刺参(Apostichopus japonicus)生长、体组成及免疫指标的影响

在基础饲料中分别添加0、10％、20％、30％、40％的玉米干酒精糟及其可溶物(Dried distiller's grains with solubles,DDGS),配制成5种等氮等能的实验饲料(DDGS0、DDGS10、DDGS20、DDGS30 和DDGS40),饲喂初始体重为(9.69±0.28)g的刺参56 d,研究玉米DDGS作为替代蛋白源对其生长、体成分及免疫指标的影响.结果显示,随着玉米DDGS添加水平的升高,刺参增重率和特定生长率略有下降,但各组间差异不显著(P＞0.05).各实验组刺参体壁指数、肠道指数、肠长比以及体壁水分、粗蛋白、粗脂肪和粗灰分含量均不受玉米DDGS添加的影响(P＞0.05).体腔液中溶菌酶的活性呈先上升后稳定的趋势,其中,DDGS20和DDGS40组显著高于DDGS0和DDGS 10组(P＜0.05),DDGS30组与其他各组无显著差异(P＞0.05).酸性磷酸酶的活性呈先上升后下降的趋势,在DDGS20组达到最大值,其中,DDGS20组显著高于其他各组(P＜0.05),DDGS40组显著高于DDGS0组(P＜0.05),其他各组间无显著差异(P＞0.05).酚氧化酶的活性随着DDGS添加量的增加呈上升趋势,各添加组均显著高于DDGS0组(P＜0.05),DDGS40组显著高于DDGS 10组(P＜0.05),其他各组间无显著差异(P＞0.05).饲料中添加玉米DDGS对体腔液中碱性磷酸酶和超氧化物歧化酶的活性无显著影响(P＞0.05).本研究表明,饲料中添加0-40％的玉米DDGS均不影响刺参的生长和体壁成分,且添加20％-40％的玉米DDGS能提高刺参体腔液中免疫酶的活性.     

Amino acid digestibility of heat damaged distillers dried grains with solubles fed to pigs

The primary objective of this experiment was to determine the effects of heat treatment on the standardized ileal digestibility(SID) of amino acids(AA) in corn distillers dried grains with solubles(DDGS) fed to growing pigs. The second objective was to develop regression equations that may be used to predict the concentration of SID AA in corn DDGS. A source of corn DDGS was divided into 4 batches that were either not autoclaved or autoclaved at130°C for 10, 20, or 30 min. Four diets containing DDGS from each of the 4 batches were formulated with DDGS being the only source of AA and CP in the diets. A N-free diet also was formulated and used to determine the basal endogenous losses of CP and AA. Ten growing pigs(initial BW: 53.5 ± 3.9 kg) were surgically equipped with a T-cannula in the distal ileum and allotted to a replicated 5 × 4 Youden square design with 5 diets and 4 periods in each square. The SID of CP decreased linearly(P 0.05) from 77.9% in non-autoclaved DDGS to 72.1, 66.1, and 68.5% in the DDGS samples that were autoclaved for 10, 20, or 30 min, respectively. The SID of lysine was quadratically reduced(P 0.05) from 66.8% in the non-autoclaved DDGS to 54.9, 55.3, and 51.9% in the DDGS autoclaved for 10, 20, or30 min, respectively. The concentrations of SID Arginine, Histidine, Leucine, Lysine, Methionine, Phenylalanine, or Threonine may be best predicted by equations that include the concentration of acid detergent insoluble N in the model(r2= 0.76, 0.68, 0.67, 0.84, 0.76, 0.73, or 0.54, respectively). The concentrations of SID Isoleucine and Valine were predicted(r2= 0.58 and 0.54, respectively) by the Lysine:CP ratio, whereas the concentration of SID Tryptophan was predicted(r2= 0.70) by the analyzed concentration of Tryptophan in DDGS. In conclusion, the SID of AA is decreased as a result of heat damage and the concentration of SID AA in heat-damaged DDGS may be predicted by regression equations developed in this experiment.     

测定小麦籽粒中全磷含量的2种消解方法比较

在小麦籽粒全磷含量测定中,比较了电炉法和消煮炉法消解样品的效果,结果表明:2种方法的消解效果一致,但消煮炉法比电炉法更方便。     

内蒙古草原针茅属六种植物的花粉形态研究

作者对内蒙古天然草原六种针茅属植物的花粉粒进行扫描电子显微镜观察，发现在花粉粒大小，萌发孔直径，颗粒状纹饰的粗细及孔环特征等性状方面均有显著差异。     

酒精性发酵功能乳饮料——开菲尔的研究进展

作为一种古老而又新型的发酵奶制品,Kefir的营养特性及其保健功能,愈来愈受到人们的喜爱。本文介绍了Kefir及其发酵剂开菲尔粒,并对Kefir的营养特性、功能特性及其相关制品的研究进展做一综述,对Kefir的研究进行了展望。