Performance of legume–grass mixtures in the West Balkan region

Three perennial legumes (alfalfa, red clover and birdsfoot trefoil) and four cool-season perennial grasses (orchardgrass, tall fescue, Italian ryegrass and red fescue) were grown in legume–grass combinations and in pure stands of individual species, at three locations in the West Balkan region (Novi Sad, Banja Luka and Pristina) in the period from 2012 to 2015. The study evaluated dry matter yield, legume–grass–weed proportion and forage quality. High annual forage yield of legume–grass mixtures can be obtained with proper selection of species and an appropriate legume–grass ratio. However, high and stable yield, particularly in the case of grasses, depends on the amount and schedule of precipitation as well as the cutting time. The mixtures and legume pure stands achieved better forage production both per cutting and on the annual basis and had better forage quality than grass pure stands.     

Enzootic ulcer in the back of the tongue in cattle after ingestion of hay containing flower clusters of yellow bristle-grass

Chronically recidivating enzootic ulcerations in the tongues of numerous milking cows in the Po river plain area in Italy. The animals were permanently kept indoors in cubicle houses and fed by hay containing high amounts of ripe yellow bristle grass (Setaria glauca (L.) Beauv. [= S. pumila Poiret]). The panicled parts of the culms were found to be the cause of the massive injuries.     

农杆菌介导茎尖转化体系对不同基因型棉花转化率的影响

选用两种不同基因型陆地棉华抗6号和06S62为材料,以无菌黄化苗茎尖为受体,用农杆菌介导法进行转化,对不同的菌液浓度、浸染时间和负压处理等进行了比较试验,探讨农杆菌介导对两种不同基因型棉花遗传转化率的影响。结果表明,农杆菌介导棉花转化的适宜条件是：对于华抗6号,菌液浓度OD600达到0.7、浸染时间10min、负压处理10min时,转化的效果较好;对于06S62,菌液浓度OD600达到0.9、浸染时间15min、负压处理15min时,转化的效果较好,华抗6号的转化率高于06S62,其最高转化率为8.81%。通过该茎尖遗传转化体系,将bar导入上述两个基因型棉花获得了抗除草剂的转基因植株。     

Valuation of Rice Postharvest Losses in Sub-Saharan Africa and Its Mitigation Strategies

正Data on rice harvest and postharvest loss in Sub-Sahara Africa(SSA) is scanty making it difficult for stakeholders to appreciate the loss and set priority areas for loss reduction along the value chain. To address this problem, a protocol was developed and validated for postharvest loss(PHL) quantification in SSA. Quantitative losses at each segment were determined by field measurements.     

Attosecond synchronization of high-harmonic soft x-rays

Subfemtosecond light pulses can be obtained by superposing several high harmonics of an intense laser pulse. Provided that the harmonics are emitted simultaneously, increasing their number should result in shorter pulses. However, we found that the high harmonics were not synchronized on an attosecond time scale, thus setting a lower limit to the achievable x-ray pulse duration. We showed that the synchronization could be improved considerably by controlling the underlying ultrafast electron dynamics, to provide pulses of 130 attoseconds in duration. We discuss the possibility of achieving even shorter pulses, which would allow us to track fast electron processes in matter.     

Magnetic properties of surface sediments in Schirmacher Oasis,East Antarctica: spatial distribution and controlling factors

Journal of Soils and Sediments - We investigated the magnetic properties (abundance, grain size, and mineralogy) of iron oxides present in Lake L-55 sediments, Schirmacher Oasis, East Antarctica,...     

Effect of Essential Oils from Citrus Varieties on in vitro Growth and Sporulation of Phaeoramularia angolensis Causing Citrus Leaf and Fruit Spot Disease

Citrus leaf and fruit spot disease caused by Phaeoramularia angolensis is a serious production constraint in tropical Africa. In previous studies, essential oils extracted from fruit peels of two tolerant varieties exhibited a strong antifungal activity in vitro against P. angolensis as compared to oils from susceptible ones. In order to investigate if the susceptibility of citrus varieties is associated with the antifungal activity of their essential oils, some 22 varieties of different susceptibility levels (tolerant, susceptible and highly susceptible) and belonging to different botanical groups were studied. Oils extracted from fruit peels were evaluated for their activity against radial growth and sporulation using the poisoned food technique. The optimal doses for growth inhibition and conidial reduction were 2500 and 1000 ppm, respectively. At these doses, radial growth and sporulation exceeded the untreated control respectively for four and nine varieties suggesting that oils from these varieties promote fungal development. In general, oils from the tolerant group were most effective in reducing radial growth irrespective of dose. The highly susceptible group ranked first in reducing sporulation at dose 1000 ppm (45.93%) while at higher doses of about 2000–2500 ppm, oils from the tolerant varieties could reduce sporulation up to 100%. The marked dose effect in reducing sporulation suggests that there may be different compounds acting with changing dose. Botanically, oils from pummelo (Citrus maxima, tolerant group), were best in reducing radial growth (>87% inhibition) while those from grapefruits (C. paradisi, highly susceptible group) were most effective in reducing sporulation (>64% reduction).     

农杆菌介导茎尖转化体系对不同基因型棉花转化率的影响

选用两种不同基因型陆地棉华抗6号和06S62为材料,以无菌黄化苗茎尖为受体,用农杆菌介导法进行转化,对不同的菌液浓度、浸染时间和负压处理等进行了比较试验,探讨农杆菌介导对两种不同基因型棉花遗传转化率的影响.结果表明,农杆菌介导棉花转化的适宜条件是:对于华抗6号,菌液浓度OD600达到0.7、浸染时间10 min、负压处理10 min时,转化效果较好;对于06S62,菌液浓度OD600达到0.9、浸染时间15-min、负压处理15 min时,转化效果较好;华抗6号的转化率高于06S62,其最高转化率为8.81%.通过该茎尖遗传转化体系,将bar导入上述两种基因型棉花获得了抗除草剂的转基因植株.     

EGFP-Rhm51 foci enable the visualization and enumeration of DNA double-strand breaks in <Emphasis Type="Italic">Magnaporthe oryzae</Emphasis>

To detect and count DNA double-strand breaks (DSBs) during the life cycle of Magnaporthe oryzae, we constructed an expression vector for EGFP-Rhm51 fusion protein and introduced it into strain Ina86-137. EGFP-Rhm51 foci were detected, and the number of foci in mycelia treated with mitomycin C, which induces DSBs, was higher than in untreated samples, indicating that the foci enabled the visualization of DSBs during the life cycle. EGFP-Rhm51 foci were observed at all stages of the asexual cycle including when invasive hyphae formed in an intact rice leaf sheath, demonstrating that M. oryzae undergoes DSBs during vegetative and parasitic growth.     

温度诱导对星豹蛛热激蛋白hsp70和hsp90基因表达的影响

为探讨温度诱导对星豹蛛的应激反应,运用实时定量PCR法测定了不同温度对星豹蛛热激蛋白hsp70和hsp90基因表达量的影响。结果表明:经过17、20、23、26℃诱导后,星豹蛛hsp70和hsp90基因表达量与对照组差异不显著,当高于26℃时,随着温度的升高表达量呈先升高后降低的趋势,且在38℃时最高,分别为对照组的716.46和10.44倍,差异显著;低于17℃时,表达量随着温度的降低呈逐渐升高的趋势,其中-1℃时最高,分别为对照组的334.53和9.38倍,差异显著;-1~41℃范围内,在相同诱导温度处理下,星豹蛛hsp70基因表达量显著高于hsp90基因。表明当星豹蛛受到温度高于26℃或低于17℃的刺激后,体内hsp70和hsp90基因表达量均增加,且hsp70基因表达量高于hsp90基因。说明热激蛋白只有在极端高温和低温的条件下才充分表达,从而对机体产生保护作用,且这种保护只在一定温度范围内起作用。