Application of low intensity light pulses to delay postharvest senescence of Ocimum basilicum leaves

Fresh basil (Ocimum basilicum L.) is a highly perishable leafy green vegetable with a storage life of 4–5 d at room temperature. Exposure of basil leaves to temperatures below 12 °C during storage results in chilling injury; therefore, refrigeration cannot be used to extend postharvest life of basil. Typically, leafy vegetables are stored in darkness or extremely low irradiance. Darkness is known to induce senescence, and the initial phase of senescence is reversible by exposure to light. In this work, we studied the effects of low-intensity white light pulses at room temperature on postharvest senescence of basil leaves. Daily exposure for 2 h to 30–37 μmol m⁻² s⁻¹ of light was effective to delay postharvest senescence of basil leaves. Chlorophyll and protein levels decreased, ammonium accumulated and leaves developed visual symptoms of deterioration (darkening) during storage in darkness. Light pulses reduced the intensity of these senescence symptoms. The photosynthesis light compensation point of basil leaves was 50 μmol m⁻² s⁻¹ i.e., higher than the intensity used in this study, and the effect of treatment with red light was the same as with white light, while far red light was ineffective. Light pulses exerted a local effect on chlorophyll loss, but the effect on protein degradation was systemic (i.e., spreading beyond the illuminated parts of the leaf blade). The results of this study indicate that daily treatment for 2 h with low intensity light (30–37 μmol m⁻² s⁻¹ every day) during storage at 20 °C is an effective treatment to delay postharvest senescence of basil leaves. The delay of postharvest senescence by low intensity light pulses seems to be mediated by phytochromes, and it is systemic for protein, and partially systemic for chlorophyll degradation.     

晋南地区红富士苹果贮后品质劣变的原因及防范措施

在对近年来山西省晋南地区红富士苹果采后贮藏过程中出现的风味品质下降、虎皮病、果肉果心褐变、耐贮性下降等问题进行深入调查研究的基础上,总结了采收与采后环节引起红富士苹果贮后品质劣变的原因,并提出了相应的防范措施。     

黄精种子形态及发芽特性研究

研究了黄精果实及种子不同发育时期内源激素ABA含量的变化与收获种子类型,以及不同类型黄精种子形态、生活力、千粒重与发芽的相关性.结果表明:3种类型黄精种子属不同发育时期的种子,其外观形态和各种物理特性指标都存在一定差异,其中黄皮种子最大,长、宽平均值分别为4.372 mm和3.710 mm,活性较弱,发芽率45.16%;绿皮种子的千粒重、生活力、发芽率均最高,分别为35.6 g、85%和85.71%;黑皮种子基本没有生活力.说明绿皮种子质量最好,黄皮种子次之.     

贮藏期间红富士苹果虎皮病发病因素分析及应对措施

综述与分析引起红富士苹果贮藏后期发生虎皮病的主要因素和发病机理,针对苹果采前与采后生产实际,提出相应的预防措施,以期达到防止红富士苹果虎皮病的发生,降低发病率和病情指数的目的。     

河南省郏县红牛肠道寄生虫感染情况调查

为了解河南省郏县红牛肠道寄生虫感染情况,采用卢戈氏碘液染色法、饱和蔗糖溶液漂浮法和改良抗酸染色法对河南省郏县地区某红牛养殖场及散养红牛的218份新鲜粪便样本进行了检查,结果发现寄生虫总感染率为66.5%,共检出4种肠道寄生虫,其中球虫、圆线虫、鞭虫和绦虫感染率分别为61.5%、2.3%、6.9%和7.8%,混合感染率为11.5%,阳性粪便中虫卵或卵囊感染强度以轻度感染为主。结果表明,河南省郏县红牛肠道寄生虫感染较为普遍,应加强其肠道寄生虫病的防治。     

A longitudinal study of oestrous characteristics and conception in tie-stalled and loose-housed Swedish dairy cows

The presence and importance of visual oestrous symptoms and the relation to conception, breed, housing system and milk yield were studied. Data were collected from a Swedish research herd during a 16-year period. Local, secondary and primary oestrous symptoms and an overall oestrus intensity score (OI) were studied. Decreasing trends in oestrous expression and conception rates (CR), and an increase in CR with more intensive oestrus, from 24% at OI score one (very week) to 54% at OI score five (very strong) were observed. The mean interval from first to last observed oestrus symptom was long with a large variation (54?±?SD?=?32?h). Generally, irrespectively of housing system, Swedish Red cows had higher CR, more intensive oestruses and longer oestrus durations compared to Swedish Holstein cows. Local oestrous symptoms, with CR of 24–28%, were most frequently detected, which is why more attention should be paid to local oestrous symptoms.     

环剥和红提大宝处理对红地球葡萄果实性状的影响

于2006-2008年,分别在河南新密、原阳和长垣等地研究了环剥和红提大宝500～2500倍液处理对红地球葡萄果穗重、果粒重、可溶性固形物含量(SSC)、着色指数、果粒纵横径、果形指数等果实性状的影响。结果表明,在红地球葡萄果粒横径14～17mm时进行主干环剥,可增加果粒重10%左右,促进着色,略微提高SSC;相同时期使用红提大宝1500～2000倍水溶液浸蘸或喷施果穗,可显著增加果粒重和穗重,增加果粒纵径和横径,对果穗其他性状影响不大。     

模糊层次分析法为基础的东北地区鹿类动物生境评价体系初探

生境是生物生活繁衍的场所,由生物与非生物因子构成。近几个世纪以来,物种灭绝的速度加快,最重要的原因是生境被破坏。生境评价,是分析物种种群数量减少和濒危原因的重要手段。因此,在对国内外马鹿生境评价的理论和实践进行分析和研究的基础上,提出了以模糊层次分析法为基础的东北马鹿生境的评价体系。对东北马鹿生境的评价,将为管理部门对东北地区马鹿生境的规划、管理和保护提供科学的决策依据。     

Effects of prescribed fire on canopy foliar chemistry and suitability for an insect herbivore

We assessed the effects of a prescribed fire on the phytochemical characteristics and vigor of overstory chestnut oak, scarlet oak, and red maple, and measured the impact of potential changes on herbivore fitness. We compared foliar carbohydrates, tannins, nutrients, and fiber concentrations in foliage from burned and non-burned forest canopies. There were significant differences in most foliar characteristics between tree species. Total non-structural carbohydrate concentrations in scarlet oak and red maple foliage, and calcium levels in red maple foliage, were significantly lower in burned plots, but other phytochemical characteristics were largely unaffected by burning. Tree growth also varied with species. Burning increased chestnut oak relative growth, decreased scarlet oak growth, and had no affect on red maple growth. Scarlet oak and red maple foliage from burned and non-burned forest canopies were assayed for gypsy moth performance. Caterpillars fed foliage from scarlet oak, the preferred host, grew larger and developed more rapidly than did those fed red maple foliage. There were no significant burn treatment differences in caterpillar development within either tree species, suggesting that managers using prescribed fire to promote oak regeneration need not worry about enhancing forest stand susceptibility to gypsy moth. However, the fire in this study was of low to moderate intensity; more intense fires may alter foliar palatability.     

平凉红牛遗传资源及选育策略

本文综述了平凉红牛遗传资源的形成过程,保护与利用现状及存在的问题,提出了“先保再用”的保护利用策略,即：先申请认定为地方品种,列入国家地方品种保护目录,划定保护区先保护,固定前期选育成果;再系统规划开展平凉红牛遗传资源本品种选育和以此为育种素材的新品种选育,以期为“保护好平凉红牛地方品种,早日育成新品种”提供参考。