梨的贮藏特性及保鲜技术

本文结合梨果的生物学特性和贮藏特性，对梨果在生产实践中做好贮藏保鲜的主要技术措施进行探讨，为梨产业的发展提供参考。     

几种农药对菜青虫的防治试验

试验了几种农药对花椰菜菜青虫（Pieris rapae sp）的防治效果，结果表明：4种农药均较好，其中以海正集团生产的三令最好，施药后3～7d防治效果达100%；杨康和武大绿洲3号A次之，防效在93%以上；绿宇较差，防效在88%以上。     

朱鹮粪样睾酮和雌二醇水平的初步测定

本试验通过粪样睾酮（T）和雌二醇（17B-B）水平的测定，建立了一种简单易行的朱鹩粪样激素测定方法。结果表明，雌鸟粪中雌二醇水平显著高于雄鸟，分别为672．65±97．39ng/g和68．28±32．03ng/g；雄乌粪中睾酮水平显著高于雌乌，分别为2527．95±1100．51ng/g和327．77±132．62ng/g。以粪样代替血样，作为一种非损伤性的采样方法，在自然状态下监测朱鹩体内激素水平的变化，为进一步开展朱鹩的生殖内分泌研究提供了新的思路。     

磷酸二酯酶在猪卵巢的表达与相关中药对其活性的影响

为了测定猪卵巢组织磷酸二酯酶（PDE）同工酶基因表达类型与活性规律，研究相关中药的作用机理，为繁殖障碍性疾病治疗积累资料。作者提取中国实验用小型猪卵巢组织总RNA，应用反转录聚合酶链反应（RT-PCR）测定PDE同工酶在其中的表达。选取催情散等复方及单味药，运用高效液相色谱法（HPLC）根据作用前后cAMP/cGMP含量的变化，分析对PDE活性的影响。结果检测的18个PDE亚型中除PDE4C外，PDE 1A、1B、1C、2A、3A、3B、4A、4B、4D、5A、7A、7B、8A、8B、9A、10A、11A mRNA在卵巢组织中均有表达。卵巢组织PDE活性较强，其中cGMP-PDE活性大于cAMP-PDE活性。催情散对卵巢组织cGMP-PDE活性均有较强的抑制作用，其中单味药淫阳藿作用最强。研究结果表明卵巢组织含有丰富的PDE同工酶，在通过环核苷酸水平卵巢机能调节中发挥着重要作用，中药催情散的作用与显著抑制cGMP-PDE活性有关。     

灵芝和菌糠降低鸡蛋胆固醇的试验研究

选取48周龄海兰褐商品蛋鸡120羽,随机分成3组,试验期为4周,对照组Ⅰ组喂基础日粮,试验Ⅱ组添加2.5g/kg灵芝,试验Ⅲ组添加2.5g/kg菌糠,在一致的背景下,探讨灵芝、菌糠对鸡蛋胆固醇的影响。结果表明:Ⅱ、Ⅲ组可降低蛋鸡血液甘油三酯(TG)、总胆固醇(TC)含量,增高血清高密度脂蛋白胆固醇(HDL-C)含量;3组之间料蛋比差异显著,Ⅱ、Ⅲ组料蛋比分别比对照组低6.4%(P<0.05)、11.0%(P<0.05)。Ⅱ、Ⅲ组平均产蛋率分别比对照组提高5.38%(P<0.05)和3.29%(P<0.05)。试验4周,Ⅱ、Ⅲ组鸡蛋胆固醇含量分别降低15.3%(P<0.05)和10.4%(P<0.05),且两组间差异显著(P<0.05),研究表明灵芝及菌糠均能提高蛋鸡生产性能,降低鸡蛋胆固醇含量。相比之下,灵芝是降低鸡蛋胆固醇较为理想的添加剂。     

High frequency plantlet regeneration from callus and artificial seed production of rock plant Pogonatherum paniceum (Lam.) Hack. (Poaceae)

Pogonatherum paniceum (Lam.) Hack. is a rock plant with good potential for vegetative recovery on naked lands. A high frequency in vitro regeneration system was developed for P. paniceum. Calli were induced from explants of mature seeds, seedlings, young leaves, and stem segments on Murashige and Skoog (MS) medium supplemented with 1.0 mg L⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D), 2.0 mg L⁻¹ α-naphthalene acetic acid (NAA) and 0.2 mg L⁻¹ 6-benzylaminopurine (BAP). High induction rates (59.57%) and regeneration rates (100%) were obtained from mature seed explants; calli were sub-cultured for over 2 years and still retained a high regenerative capacity. One seed explant resulted in 69,997 plants in 1 year. Shoot buds derived from calli were used for encapsulation in liquid MS medium containing 3% sucrose and two different alginate matrices (3% sodium alginate (w/v) + MS medium containing 3% sucrose and 3% sodium alginate + 1% activated carbon (w/v) + MS medium containing 3% sucrose) with a 20-min exposure to 2% CaCl₂ and 0.3% bavistin (w/v). The capsule with 3.0% sodium alginate (w/v) and 1% activated carbon (w/v) showed a higher conversion rate (61.58%) and stronger plantlets under non-aseptic conditions. These systems are useful for the rapid clonal propagation and dissemination of artificial seed material of P. paniceum for eco-recovery.     

Diploid female gametes induced by colchicine in Oriental lilies

The young flower buds of diploid Oriental cultivars: ‘Con. Amore’ and ‘Acapulco’ (Lilium) were treated with 0.02, 0.05, 0.1, and 0.2% colchicine to induce diploid egg (female gamete). The treated young buds between the two cultivars were crossed reciprocally as female parents with normal pollen respectively. The polyploid plants were identified by measuring stoma size and chromosome number. The results showed: that triploid progenies could be obtained through this way, and the fact that the treated young flower buds were successfully used as female parents indicated the formation of 2n or 2x egg cells. The above results implied that polyploidization by artificially induced diploid female gametes could be a powerful method to create novel variations in the breeding of Oriental lilies.     

白菜抗小菜蛾网室鉴定和离体鉴定方法比较

以8份白菜自交系材料为试材,分别利用网室鉴定和离体鉴定两种方法进行抗虫性鉴定。结果表明,两种鉴定方法的结果基本一致,材料间对小菜蛾抗性均表现极显著差异;在网室鉴定和离体鉴定中,599-3-7均表现高抗,519-3-3均表现中抗,而114-4-4和116-4-4都表现高感,部分材料的表现稍有差异;两种鉴定方法的相关系数为0.96,达到极显著水平;离体鉴定和网室鉴定相结合,能准确、全面地研究植物对小菜蛾的抗性及抗虫机理。     

Protocol: a highly sensitive RT-PCR method for detection and quantification of microRNAs

MicroRNAs (miRNAs) are a class of small non-coding RNAs with a critical role in development and environmental responses. Efficient and reliable detection of miRNAs is an essential step towards understanding their roles in specific cells and tissues. However, gel-based assays currently used to detect miRNAs are very limited in terms of throughput, sensitivity and specificity. Here we provide protocols for detection and quantification of miRNAs by RT-PCR. We describe an end-point and real-time looped RT-PCR procedure and demonstrate detection of miRNAs from as little as 20 pg of plant tissue total RNA and from total RNA isolated from as little as 0.1 μl of phloem sap. In addition, we have developed an alternative real-time PCR assay that can further improve specificity when detecting low abundant miRNAs. Using this assay, we have demonstrated that miRNAs are differentially expressed in the phloem sap and the surrounding vascular tissue. This method enables fast, sensitive and specific miRNA expression profiling and is suitable for facilitation of high-throughput detection and quantification of miRNA expression.