玫瑰黄链霉菌对根结线虫的防效及对土壤微生物区系的影响

利用玫瑰黄链霉菌Men-myco-93-63 菌株的固、液体发酵物防治设施番茄和黄瓜根结线虫,研究其对根结线虫的防效以及施用生防菌对土壤微生物区系的影响。结果表明：Men-myco-93-63 菌株固体发酵物1 V∶200 V对黄瓜和番茄根结线虫病的防效分别达到了65.62% 和57.69%;施用生防菌使得植株根际土壤中细菌数量增加了19.57%,放线菌数量增加了316.67%,真菌数量降低了28.57%,以上3 种可培养微生物总量由7.4×10⁶ cfu·g^-1增加到16.75×10⁶ cfu·g^-1,增加了126.35%。     

动物性控精液的分离及纯度评价方法的研究进展

性控技术可以加速优良种畜的繁育速度,有效发挥母畜的繁殖潜力,为乳用动物提供母畜,为肉用动物提供公畜。将雄性动物精液分离不但可以提高后代质量,而且可提高繁殖效率。动物性控精液的分离作为动物遗传育种的重要组成部分,为畜牧业发展起到了重要作用。本文综述了流式细胞仪分离精液的研究进展及精液纯度评价方法,以期为新方法的探索提供参考。     

基施尿素对片麻岩新成土旱地谷子生长及土壤硝态氮时空分布的影响

本试验在片麻岩新成山地土壤上,设置0(CK)、N 120kg/hm2(N120)、N 225 kg/hm2(N225)、N 300kg/hm2(N300)4个施氮水平,布置田间微区试验,小区面积为10m2,研究了尿素不同施用量对旱地谷子生长及土壤硝态氮时空分布的影响。定位试验第二年的结果表明:在该试验条件下,N120处理谷子产量达到最高为4.76 kg/10m2,之后提高施肥量N225和N300处理的谷子产量并没有显著增加;从0~60 cm土壤剖面中硝态氮时空分布的差异可以看出:在施肥20 d后,N120、N225和N300处理NO3--N含量在0~40 cm土层显著增加,其中N225和N300处理NO3--N已经下移到40~60 cm土层。施肥80 d后,各施肥处理的硝态氮有一部分已经移出60 cm土层。到施肥96 d(谷子收获),N120、N225和N300处理比CK处理土壤剖面中NO3--N含量显著增加,且氮肥用量越高,土壤中NO3--N含量越高。     

23份中国小麦微核心种质抗叶锈性评价

【目的】探测23份微核心种质材料的抗叶锈性和可能携带的抗叶锈基因。【方法】选取12个具有鉴别能力的小麦叶锈菌生理小种对23份微核心种质进行了苗期和成株期的抗性鉴定以及基因推导,同时结合使用已经报道的能够用于抗病基因分子鉴定的分子标记对其进行进一步抗叶锈基因的分子检测。【结果】这些品种中除中国春表现感病外,其余22份种质均表现出较强的抗性。火球、老齐麦、凤麦11、山红麦、红和尚头、府麦、尕老汉和郑引4号含Lr34和未知抗性基因,中国春含Lr34,碱麦和小佛手含Lr1和Lr34,同家坝小麦和红花麦含Lr34和Lr32,克丰3号含有Lr10、Lr34、Lr16和Lr32,Atlas66含有Lr1、Lr2c和Lr32,烟农15含Lr1,可能含有Lr17,白条鱼含Lr26、Lr16、Lr42和LrZH84,木宗卓嘎含Lr26,可能含Lr14a,金黄麦含Lr1、Lr34和Lr32,云麦34含Lr26、Lr37和LrZH84,可能含有Lr15,百农3217含Lr1和Lr16,白朗灰麦和山麦可能含有未知抗叶锈基因。【结论】这些小麦微核心种质中含有比较丰富的抗叶锈基因,具有较好的抗叶锈性,是抗叶锈育种的重要资源。     

不同播期覆膜处理对雪莲果产量及品质的影响

通过覆膜保温措施,在中纬度地区研究了不同播期处理对雪莲果块根产量及品质的影响,以期为雪莲果在中纬度地区的优质高产栽培提供理论依据。结果表明:雪莲果块根产量以播期为3月16日覆膜处理最高,且随着播期的推迟呈逐渐降低趋势;播期为4月15日覆膜处理的产量与播期为4月25日不覆膜处理差异不显著。播期为3月26日覆膜处理的块根品质较好,可溶性固形物含量、可溶性蛋白含量和可溶性糖含量均最高;Vc含量以播期为3月16日覆膜处理最高;可滴定酸含量随着播期的推迟而逐渐升高。因此认为,在中纬度地区适时覆膜提早播期,可以显著提高雪莲果的产量和品质,但是栽种定植过早会影响块根品质。本研究覆膜条件下,中纬度地区雪莲果获得优质高产的最佳播期是3月26日。     

14个小麦品种(系)抗叶锈性分析

选用16个小麦叶锈菌菌系对14个小麦品种(系)进行抗叶锈性鉴定和苗期抗叶锈基因推导,初步分析这些品种(系)的抗性和携带的抗病基因;进一步利用21个与Lr基因紧密连锁或共分离的分子标记,对这14个品种(系)中可能含的抗叶锈基因进行鉴定。结果表明,s98351-2-2-2-1可能含Lr3a、Lr28和Lr50;9629-03A-4-1-1可能含Lr37;97167-1-2-1-1-2-1、919-20-2c2、9589、免中438、9916-8-6和9916-8-18含Lr26;96104-1-5-1c2可能含Lr28;00-55-3-1-1含Lr1;1R13可能含Lr24、Lr37和Lr38;1R17可能含Lr24和Lr38;1R35含Lr10和Lr34,还可能含Lr3a和Lr50;9524-1-2-2-1含未知抗叶锈基因或本试验使用的已知抗病基因以外的抗叶锈基因。所有品种(系)均不含Lr9、Lr19、Lr20、Lr21、Lr29、Lr35、Lr42和Lr47基因。测试的14个品种(系)中有比较丰富的抗叶锈病基因,可为育种提供丰富的抗源。     

高产田夏玉米季土壤中酶及微生物特性的动态变化特征

以河北山前平原现有高产田为研究对象,以周边常规农田为对照,研究了秸秆还田条件下夏玉米生长季土壤酶活性及微生物特性的动态变化特征。结果表明:两种农田上层(0～20 cm)土壤酶活性较强,且高产田土壤酶活性整体显示出高于常规农田;在不同的土层中,各土壤酶的活性随生育期的动态变化趋势基本一致,在玉米生长旺盛阶段活性较高,其中高产田土壤磷酸酶活性显著高于常规农田(P0.05)。对于常规农田,玉米十叶期追施尿素有效提高了微生物活性,这有利于作物生长旺盛期的发育及还田秸秆腐解;高产田微生物量氮和微生物量磷在生育期内整体上高于常规农田,且表层土壤微生物量磷显著高于常规农田(P0.05)。     

Presence of indigenous endophytic bacteria in jujube seedlings germinated from seeds <Emphasis Type="Italic">in vitro</Emphasis>

The presence of indigenous endophytic bacteria in tissue-cultured seedlings germinated from seeds of Zizyphus jujuba var. Fupingdazao was investigated using cultivation, light microscopy and scanning electronic microscopy (SEM). In addition, bacteria specific 16S rDNA PCR followed by denaturing gradient gel electrophoresis (DGGE) was used. No cultivable bacteria could be detected on plates or in liquid cultures. However, large quantities of endophytic bacteria in jujube seedlings were observed under the light microscope. The bacterial cells were round (measuring 1.5 μm–1.8 μm), short rods (2.2 μm − 2.9 μm × 1.1 μm − 1.9 μm) and rod shaped (3.7 μm − 4.4 μm × 1.6 μm − 1.9 μm). Rod-shaped bacterial cells (measuring 3.5 m−4.0 m × 1.5m−2.0 m) were observed by SEM as well. A 16S rDNA fragment of 1.5 kb could be amplified from the total DNA of seedlings of jujube using the bacterial primer pair 27F/1525R. The V3 fragment of 16S rDNA was separated by DGGE, and the 16S rDNA-PCR-DGGE showed that there were at least six dominant bands within the seedlings of Z. jujuba var. Fupingdazao. It can be concluded that endophytic bacteria that cannot be detected by cultivation are present with high densities in jujube seeds.     

掌叶半夏茎基腐病病原鉴定及其防治药剂筛选

茎基腐病是河北省安国市掌叶半夏（Pinellia pedatisecta）生产中为害较严重的多发性病害,对该病害的病原菌进行了分离、鉴定、致病性测定和防治药剂的筛选。通过形态鉴定和rDNA-ITS序列分析,将安国掌叶半夏茎基腐病的病原菌鉴定为瓜果腐霉（Pythium aphanidermatum）。选用5种常用化学杀菌剂、2种生物杀菌剂和玫瑰黄链霉菌Men-myco-93-63抗生素粗提物对Py. aphanidermatum进行室内毒力测定,结果表明：35%精甲霜灵ES、玫瑰黄链霉菌Men-myco-93-63抗生素粗提物、40%氟硅唑EC、99%恶霉灵TC对瓜果腐霉菌丝的生长具有较明显的抑制作用,EC₅₀分别为12.81、41.74、54.16和56.90μg/mL;而1×10 ¹¹芽孢/g枯草芽孢杆菌WP、1×10 ⁶孢子/g寡雄腐霉菌WP、3%甲霜·恶霉灵AS和50%烯酰吗啉WP对该病菌的抑制效果不明显。     

Overexpression of the apple expansin-like gene MdEXLB1 accelerates the softening of fruit texture in tomato

Fruit firmness is an important quality trait of apple fruit texture, and the pre-harvest ripening period is the key period for the formation of apple fruit texture. Expansin is a cell wall loosing protein family that has four subfamilies: α-expansin (EXPA), β-expansin (EXPB), expansin-like A (EXLA), and expansin-like B (EXLB). In this study, we investigated the key period of pre-harvest texture formation in ‘Golden Delicious’ apples based on fruit longitudinal diameter, transverse diameter, firmness, tissue structure, respiration intensity, ethylene release rate, and expansin activity. Within the 10 days before harvest, the fruit was found to reach maturity. Semi-quantitative RT-PCR revealed that most of the expansins were expressed at the ripening stage before harvest. The biological function of the EXLB subfamily gene, MdEXLB1, was further identified, and its subcellular localization on the cell wall was confirmed by transient transformation experiments. Compared with the wild type (WT), the transgenic tomato lines overexpressing MdEXLB1 had lower plant height, earlier fruiting period, fewer days for fruit ripening, higher fruit maturity, lower fruit firmness, higher fruit expansin activity, more discrete flesh cell structure, and accelerated fruit ripening process. Overall, this is the first study to propose that the apple EXLB subfamily gene, MdEXLB1, has biological functions and plays an important role in promoting fruit ripening and softening.