Precision phenotyping of contrasting potato(Solanum tuberosum L.) varieties in a novel aeroponics system for improving nitrogen use efficiency: In search of key traits and genes

With increasing population, degrading soil health, limited arable land area, and high cost of nitrogen(N) fertilizers, improving nitrogen use efficiency(NUE) of potato is an inevitable approach to save the environment and achieve sufficient tuber yields with less N fertilizer supply. Recently, we have developed an aeroponics system to study NUE in potato using genomics, physiology, and breeding approaches. This study aims on precision phenotyping of plants of two distinct potato varieties(Kufri Gaurav, N efficient; Kufri Jyoti, N inefficient) in the novel aeroponics system. Plants were grown in aeroponics under controlled conditions with low N(0.75 mmol L~(-1) NO_3~-) and high N(7.5 mmol L~(–1) NO_3~-) levels. Plant biomass, root traits, total chlorophyll content, and plant N were increased with increasing N supply, whereas higher NUE parameters namely NUE, agronomic NUE(Ag NUE), N uptake efficiency(NUp E), harvest index(HI), and N harvest index(NHI) were observed at low N. An NUE efficient cv. Kufri Gaurav showed higher tuber dry weight, fresh tuber yield, tuber number per plant, early start of tuber harvesting, root traits, stolon traits, NUE parameters, and higher amino acid(aspartic acid and asparagine) content at low N supply. Higher expression of nitrate reductase(NR), nitrite reductase(NIR), and asparagine synthetase(AS) genes was observed in the leaf tissues of Kufri Gaurav at high N. Thus, aeroponics-based precision phenotyping enables identification of NUE efficient genotypes based on key traits and genes involved in improving NUE in potato. Further, this study suggests that the potential of aeroponics can be utilized to investigate N biology in potato under different N regimes.     

拐子湖地区沙尘天气风蚀起沙量的估算

为研究沙尘暴中心在沙尘天气下风蚀起沙量和一些参数的具体情况,以巴丹吉林沙漠拐子湖地区一次沙尘天气过程为例,通过经验公式与野外仪器观测对比分析,对拐子湖地区风蚀起沙过程的一些参数进行了分析。结果表明:摩擦速度与风速成正相关,并影响着风蚀起沙量变化;临界摩擦速度为0.36m/s;估算了平均顺风向沙尘通量和垂直沙通量分别为1.7E-02kg/(m.s)和1.38E-07kg/(m2.s),顺风向沙尘通量要远大于垂直沙通量。这些参数的得出对防风治沙有着重要的意义。     

Interaction of soil microbial communities and phosphorus fractions under long-term fertilization in paddy soil

Understanding the impact of biological activities on the soil phosphorus (P) distribution under long-term fertilizer application can facilitate better soil P fertility management. Therefore, the primary objectives of this study were to investigate the effect of long-term (since 1981) fertilizer application on the soil P fractions and microbial community and to evaluate correlations between the microbial community structure and P distribution. The following treatments were implemented in a long-term field trial: no fertilization (CK), inorganic N and K (NK), inorganic P and K (PK), inorganic N, P and K (NPK) and manure+NPK (MNPK) fertilization. The study showed that the soil pH, soil organic carbon and total and available N and P concentrations were considerably higher in the MNPK treatment than in the CK treatment. The soil microbial biomass C, N and P concentrations were also significantly higher in the MNPK treatment than in the CK treatment. Among fertilization treatments, the β-1,4-glucosidase, α-1,4-glucosidase, urease, acid phosphatase and phosphodiesterase activities were the highest in the MNPK treatment. Compared to inorganic fertilization, the MNPK treatment increased the labile soil P fractions and decreased the residual soil P concentration. Continuous fertilization significantly affected the soil microbial composition. The total phospholipid fatty acid (PLFA) concentrations in the NK, PK, NPK and MNPK treatments were 23.3, 43.1, 48.7 and 87.7% higher, respectively, than in the CK treatment. A significant correlation was observed between the microbial community and soil P fractions. Moreover, the aggregated boosted tree (ABT) model showed that among the various soil biochemical properties, the total PLFA concentration was the factor that most influenced the active P pool, accounting for 35.4% of the relative influence of all soil biochemical properties examined. These findings reveal that combined manure and inorganic fertilizer application is a better approach than applying inorganic fertilizer alone for sustaining long-term P fertility by mediating soil biological activity.     

Assessment of dry matter and protein digestibilities of selected raw ingredients by discus fish (Symphysodonaequifasciata) using in vivo and in vitro methods

The reliability of several in vitro steps as compared with the conventional in vivo method to determine the dry matter and protein digestibilities of several raw ingredient by discus juveniles was assessed. In vitro studies were conducted based on a 12-h digestion method and measurement of pH drop involving four different substrate–enzyme mixtures, namely the Lazo single enzyme, Hsu multi-enzyme, Saterlee multi-enzyme and discus extract enzyme system. Results from both methods showed that fishmeal was highly digestible in terms of dry matter (67.22–87.52%) and protein (76.8–91.18%). With the exception of poultry offal meal, findings also indicate that discus digests dry matter in feedstuffs of animal origin (fish meal and beef heart) more efficiently compared with plant materials (soybean and wheat meal) with no obvious trend observed for protein digestibility in any of the ingredients tested. Apparent digestibility coefficients of not less than 40% suggest that all the ingredients tested were potential ingredients for development of formulated feed for discus culture. A comparison between the different in vitro enzyme systems tested showed that the Saterlee method, which used commercial mammalian and bacterial enzymes, was best in terms of its ability to differentiate the digestibilities of the various ingredients and correlation ( r ²=0.85–0.90) with the in vivo results. The use of a crude enzyme extract from discus digestive tract also provided values consistent with in vivo and Saterlee in vitro methods ( r ²=0.72–0.87), indicating the potential and need for further investigation to develop a more accurate in vitro assay based on discus digestive enzymes.     

哈萨克族的草原游牧文化(Ⅳ)——哈萨克族的衣、食、住、行及婚丧等生活文化

哈萨克族服饰具有浓郁的草原游牧生活的特征,冬季的服饰大多由动物的皮毛制成,夏季以布制服饰为主。为了便于骑乘,衣服都比较宽大,亦喜欢扎腰带,显得干净利落。男服讲究潇洒、实惠、舒适、方便,女服还讲究美观。足蹬长腰皮靴,头带漂亮帽子,未婚少女的帽子上要插上一撮漂亮的猫头鹰羽毛;哈萨克族的传统饮食以肉食、奶食品为主,米面食品居次,基本上不吃蔬菜,喜茶。肉食有牛肉、马肉、羊肉、骆驼肉,多以水煮肉方式食用(手抓)。奶品有牛奶、羊奶、合木孜(马奶酒)、楚巴提(骆驼奶)、奶茶、酸奶子;哈萨克族牧民在春、夏、秋季住的是便于拆卸和携带的圆形毡房,冬天则住霍斯(简易哈萨克毡房)或土房;哈萨克族限制同一部落的男女结亲,婚俗从说亲到完婚要经过六个阶段:提亲、订婚、"吉尔提斯"仪式、送彩礼、出嫁、迎亲;哈萨克族十分重视儿童成长。出生后七天后举行"别斯科哲尔"(摇篮礼)並取名,40天后要举行40天礼,2～3岁时举行"恰式阿鲁"(剪发礼),男孩子3岁、5岁或7岁时要举行"笋跌特"(割礼),5～7岁时举行骑马礼,第一次打回猎物狩猎时要举行狩猎礼;哈萨克族按伊斯兰教的规定举行葬礼,要点是速葬、简葬和土葬。程序是用水净身,白纱布包裹尸体(克凡),举行"加纳扎"(站礼),入土为安。     

Breeding for pre-harvest sprouting resistance in bread wheat under rainfed conditions

Pre-harvest sprouting in wheat is the germination of seeds within the spikes when rains occur after or during grain ripening, which occurs commonly in the barani tract of Pakistan. Therefore, 10 cultivars and five advanced lines of spring bread wheat were evaluated for pre-harvest sprouting resistance. After natural rainfall, seeds were immediately collected from the wet spikes and tested for germinating ability. Three different germination tests were applied to hand-threshed seed: (1) spikes threshed on the day of sampling and germination tested immediately, (2) spikes threshed on the day of sampling and germination tested 1 week later, and (3) spikes threshed 1 week after sampling and germination test immediately after threshing. Seeds and spikes kept for 1 week were place on blotting paper at room temperature. Cultivars BARS-09, 09FJ17, Doukkala-12, NARC-09 and Ouassou-20 exhibited higher sprouting resistance while other genotypes were susceptible to pre-harvest sprouting in each of the three tests. A diallel crossing was conducted with six susceptible and two resistant genotypes to assess the genetic behavior of pre-harvest sprouting resistance. The combining ability (CA) demonstrated a higher proportion of additive genetic effects for sprouting resistance, because of higher variance of general and specific CA for both parameters under study. Doukkala-12 and BARS-09 showed increased pre-harvest sprouting resistance in their F₁ descendants.     

塔克拉玛干沙漠地表温度时空变化特征研究

地表温度(LST)是重要的气候变量之一,是陆面过程地-气相互作用的一个重要参数.研究利用塔克拉玛干沙漠腹地2017年观测数据,分析该地区地表温度年内变化特征.结果表明,沙漠腹地地表温度季节变化明显,昼夜温度变化波动幅度大,年内日均温最高值出现在7月,最低值出现在1月,四季的日内温度变化特征基本一致,日最低温均出现在当地...     

不同去势程度对筠连黄牛生长性能、血清指标和瘤胃发酵的影响

本试验旨在对不同去势程度筠连黄牛的生长性能、血清指标和瘤胃发酵进行探究。选取18头年龄(9月龄)和体重[(184.46±17.37) kg]相近的健康筠连黄牛公牛,随机分为3组(双去势组、半去势组和假手术组),每组6头牛,饲喂相同饲粮,不同程度去势后,进行240 d的饲养试验。结果表明：1)与假手术相比,双去势能够显著降低筠连黄牛的体重和平均日增重(P≤0.05),而半去势对体重和平均日增重无显著影响(P>0.05);去势程度不会影响筠连黄牛的干物质采食量和营养物质摄入量(P>0.05)。2)双去势组筠连黄牛血清睾酮和生长激素浓度显著低于假手术组(P≤0.05),而血清雌二醇、胰岛素和生长抑素浓度则显著高于假手术组(P≤0.05);半去势对血清各激素浓度无显著影响(P>0.05)。3)与假手术相比,双去势导致筠连黄牛血清低密度脂蛋白浓度、谷草转氨酶和碱性磷酸酶活性显著升高(P≤0.05),血清游离脂肪酸、总蛋白和球蛋白浓度显著降低(P≤0.05)。4)与假手术组相比,双去势组筠连黄牛瘤胃液pH显著升高(P≤0.05),但瘤胃液氨态氮、微生物蛋白和挥发性脂肪酸(除丁酸和...     

Confirmed resistance to aryloxyphenoxypropionate herbicides in Phalaris minor populations in Iran

Phalaris minor (littleseed canary grass) is a major weed in wheat fields in some parts of Iran. Diclofop‐methyl, fenoxaprop‐P‐ethyl, and clodinafop‐propargyl are three acetyl coenzyme A carboxylase (ACCase)‐inhibiting herbicides that are commonly used to control this grass in wheat fields. Thirty‐four P. minor populations with suspected resistance to ACCase‐inhibiting herbicides were sampled from wheat fields in the provinces of Fars and Golestan in Iran. The dose–response assays that were conducted under controlled greenhouse conditions indicated that 14 populations were resistant to fenoxaprop‐P‐ethyl, seven populations were resistant to both fenoxaprop‐P‐ethyl and diclofop‐methyl, and three populations were resistant to fenoxaprop‐P‐ethyl, diclofop‐methyl, and clodinafop‐propargyl. These populations showed different levels of resistance to the applied herbicides, compared to the susceptible population. These results suggest that different mechanisms of resistance could be involved. The enzyme assay revealed that the existence of modified ACCase in the three most‐resistant populations (AR, MR4, and SR3) is responsible for the resistance of these populations.     

Furosemide-induced changes in plasma and blood volume of camels (Camelus dromedarius)

This work examines the effect of treatment of camels with furosemide (1 or 2 mg/kg, intravenously) on blood volume (BV), plasma volume (PV) and the plasma concentrations of total solids (PTS), plasma total protein (PTP) haemaglobin (Hb) and haematocrit (PCV). The cumulative urine produced during the 4 h following furosemide administration (2 mg/kg) averaged 22.2 mL/kg, compared to 2.3 mL/kg in controls. None of the above parameters were significantly changed by furosemide treatment at either dose.
In another experiment, the effect of the two doses of furosemide on the sequential changes on some of the above parameters was investigated at 5, 10, 15, 30, 45, 60, 75, 90, 105, 120 and 240 min after the drug administration.
On the whole, there were no significant changes in any of the measured parameters, except for small but statistically significant increases in the PCV and Hb at 30 and 45 min post treatment.
It is concluded that, despite the marked diuresis following furosemide administration, the camel appears to be able to maintain its bodily fluid haemostasis.