170份亚麻种质资源主要农艺性状分析

对来自五大洲33个国家的170份亚麻种质资源的9个农艺性状进行了分析。结果表明,参试资源的农艺性状差异较大,变异丰富。各性状间相互影响,有10对性状呈极显著相关,其中,株高、分茎数、主茎分枝数、单株果数均与单株产量呈极显著正相关,作用效应为单株果数>主茎分枝数>分茎数>株高。主成分分析表明前3个主成分的累积贡献率为74.705%。将170份种质资源划分为5类,各个类群之间差异明显。对33个国家类群进行聚类分析,分为3个组群,地理来源相同的品种被归为不同类群,洲际之间的种质资源在组群中相互渗透。     

超级杂交稻华浙优1号高产制种技术

华浙优1号是中国水稻研究所与浙江勿忘农种业股份有限公司合作选育的超级稻品种,已被列为2019年浙江省主导品种,田间种植表现出茎秆粗壮、耐肥抗倒、丰产稳产、品质优良等特点。根据不育系华浙A、恢复系H570在浙江省遂昌县制种表现,结合当地气象条件,摸索出适宜在浙西南山区开展的华浙优1号高产制种技术。     

促性腺激素及卵泡液协同对牛腔前卵泡体外发育的影响

将100个φ100～150μm牛腔前卵泡,随机分成8组,每组12～13个卵泡,在McCoy's 5a无血清培养系统研究了促卵泡素(FSH)和促黄体素(LH)有、无两种情况下,添加0、10%、15%及20%牛卵泡液(BFF)对牛腔前卵泡的体外生长、发育、存活及雌二醇(E2)分泌的影响.结果显示,在无促性腺激素下,添加不同浓度BFF对牛腔前卵泡体外发育无明显促进作用(P>0.05),但可刺激体外培养腔前卵泡的E2分泌.当有10 ng/mL LH和50 ng/mL FSH存在下,培养不同时间腔前卵泡的发育率、存活率,各卵泡液组均高于对照组,其中10%BFF组腔前卵泡培养6 d时发育率为(78.52%)与对照组(49.28%)差异显著(P<0.05),培养12 d腔前卵泡φ增长值33.7±4.8μm,显著高于对照组及其它处理组(P<0.01),同时在培养9 d时,有一枚卵泡成腔;各添加卵泡液组的E2测定值更高,其中添加10%BFF组中φ>100μm腔前卵泡在培养6 d时其E2分泌量达最高值48.96±1 1.54 pg/mL.表明FSH、LH存在下,培养液中加入10%BFF可显著提高腔前卵泡在体外的生长、发育、存活和E2分泌及诱导卵泡腔的形成.     

利用介质阻挡放电等离子体杀灭鲜榨果汁大肠杆菌

与传统热杀菌相比,非热杀菌能较大程度地保持食品中营养成分,节约能耗。为了进一步研究非热杀菌技术,利用自行设计的介质阻挡放电反应器（DBDR）,以鲜榨果汁为杀菌介质,研究了DBDR所产生的低温等离子体（LTP）的杀菌效果和对鲜榨果汁品质的影响。采用响应面法建立了介质阻挡放电等离子体（DBDP）杀灭鲜榨果汁饮料中大肠杆菌的二次多项数学模型,验证了模型的有效性,并探讨了循环次数、pH值、温度及电压对DBDP杀灭大肠杆菌的影响,优化出杀灭7个数量级大肠杆菌（E.coli）ATCC 8739的工艺参数为：循环次数6次,pH值 3.14,温度39.72℃,电压21.42 kV。为进一步研究DBDP的杀菌规律和探讨杀菌机理奠定了数学基础,同时,此模型的决定系数R2达到0.9817,可推广应用到其他果蔬汁的杀菌处理,提高鲜榨果蔬汁的品质和质量安全。     

Temperature sensitivity increases with soil organic carbon recalcitrance along an elevational gradient in the Wuyi Mountains, China

No consensus exists regarding soil organic carbon (SOC) lability and the temperature sensitivity of its decomposition. This lack of clear understanding limits the accuracy in predicting the long-term impacts of climate change on soil carbon (C) storage. In this study, we determined the temperature responses of labile and recalcitrant organic carbon (LOC vs. ROC) by comparing the time required to decompose a given amount of C at different incubation temperatures along an elevational gradient in the Wuyi Mountains in southeastern China. Results showed that the temperature sensitivity increased with increasing SOC recalcitrance (Q_10-labile = 1.39 ± 0.04 vs. Q_{10-recalcitrant} = 3.94 ± 0.30). Q_10-labile and Q_{10-recalcitrant} values significantly increased with increasing soil depth. The effect of elevational vegetation change was significant for Q_{10-recalcitrant} but not for Q_10-labile, though they increased along the elevational gradient. The response of ROC pools to changes in temperature would accelerate the soil-stored C losses in the Wuyi Mountains. Kinetic theory suggested that SOC decomposition was both temperature- and quality-dependent due to an increased temperature. This would promote more CO₂ release from recalcitrant soil organic matter (SOM) in cold regions, resulting in a greater positive feedback to global climate change than previously expected. Moreover, the response of ROC to changes in temperature will determine the magnitude of the positive feedback due to its large storage in soils.     

1-MCP和乙烯利对秋子梨采后生理及软化相关指标的影响

研究1-MCP和乙烯利处理对5种秋子梨(20±1)℃常温贮藏期间主要生理及软化相关指标的影响,探讨1-MCP和乙烯利对秋子梨品种软化机理的调控,为控制秋子梨果实后熟软化进程提供理论依据.以南果梨、京白梨、花盖梨、尖把梨和安梨5种秋子梨为试材,分别用浓度为0.5μL/L的1-MCP密闭熏蒸24 h和1.0 g/kg的乙烯利溶液浸泡5 min,比较常温((20±1)℃)贮藏期间果实硬度、可溶性固形物(SSC)、可滴定酸(TA)、维生素C(Vc)、呼吸强度、乙烯释放量等生理品质指标以及水溶性果胶、纤维素、淀粉含量、β-半乳糖苷酶(β-Gal)、淀粉酶(AM)、多聚半乳糖醛酸酶(PG)、纤维素酶(CL)等软化相关指标变化.与对照(CK)组相比,1-MCP处理可明显延缓5种秋子梨果实硬度、水溶性果胶(WSP)、纤维素、呼吸强度、乙烯释放量和淀粉含量的减少,降低了PG、β-Gal、CL、AM酶活性,而乙烯利处理组与对照组差异较小.1-MCP处理可通过抑制细胞壁相关降解酶活性和减少乙烯释放量来减轻细胞壁物质的降解,从而有效延缓秋子梨果实软化进程,而乙烯利对果实贮藏过程中软化和细胞壁降解生理变化无明显影响.     

Genetic Structure of Populations of the Pinewood Nematode Bursaphelenchus xylophilus, the Pathogen of Pine Wilt Disease, Between and Within Pine Forests

ABSTRACT We analyzed the genetic structure of Bursaphelenchus xylophilus populations within individual trees (subpopulations) in three distant pine forests (Tanashi, Tsukuba, and Chiba in Japan) based on the polymorphism of four microsatellite (SSR) markers. Most of the nematodes from subpopulations in Tanashi showed the same genotype over 2 years, indicating that nematodes of that genotype dominated there for years. In contrast, 16 and 15 genotypes were identified in nematode populations from Tsukuba and Chiba, respectively. Despite the high genetic diversity within the Tsukuba and Chiba populations, extremely low genetic diversity was observed within the subpopulations. The genetic difference between the Tsukuba and Chiba populations was significantly smaller than that between Tanashi and either Tsukuba or Chiba. Observed heterozygosity was significantly less than expected based on Hardy-Weinberg equilibrium. These findings are best explained by a founder effect, geographic isolation between populations, explosive nematode multiplication from a small number within individual trees, and the Wahlund effect.     

EMS诱变剂处理对苦荞种子萌发及主要农艺性状的影响

为探究不同甲基磺酸乙酯(ethyl methane sulfonate,EMS)浓度对苦荞种子生长发育的影响,加快苦荞品种改良的进程。本研究以‘川荞1号’、‘川荞2号’和‘川荞3号’3个品种作为试验材料,使用EMS对苦荞种子进行诱变。分别设置不同浓度梯度的EMS(0.4%,0.8%,1.2%,1.6%)处理苦荞种子,相应设置空白对照组。每个处理进行5次重复,室内调查萌发指标以及移栽后观察记录诱变植株的田间相关性状。结果显示:EMS除了对苦荞茎粗有一定的促进以外,随EMS浓度的增加,苦荞各品种全生育期延长。EMS对苦荞发芽率、根长、芽长、种苗鲜重、田间成苗率、株高以及产量方面影响显著,随着处理浓度的增加,各个指标呈递减趋势。说明EMS对苦荞植株的生长发育有明显的抑制效果。结合苦荞种子萌发相关性状、田间生长发育以及产量等方面考虑,综合得出EMS诱导苦荞适宜浓度为0.8%~1.2%。本研究为苦荞EMS诱变提供诱变时间和适宜浓度的参考。     

Octenyl succinic anhydride modified early indica rice starches differing in amylose content

Seven early indica rice starches with different amylose contents were modified by octenyl succinic anhydride (OSA) in aqueous suspension systems to evaluate the effect of amylose contents on starch esterification. The crystalline structure and pasting properties of starches were investigated using X-ray diffraction and a Rapid Visco Analyzer (RVA). The results indicated that the amylose content had a positive impact on the OSA modification. As the amylose content increased from 0 to 39.6%, the degree of substitution increased from 0.024 to 0.030 and the reaction efficiency increased from 62.8 to 77.5%. X-ray diffraction scans confirmed that the amylose was mainly present in the amorphous domain of the granule and was highly substituted after the OSA treatment. The RVA profiles demonstrated that the OSA starches had higher viscosities than their native counterparts. Moreover, negative correlations were observed between the amylose content and the major RVA parameters (e.g., peak viscosity, hot paste viscosity, cool paste viscosity, and breakdown viscosity).     

Effect of dietary lipid on growth,body composition,serum biochemistry and hepatic metabolite alteration in Chinese rice field eel (Monopterus albus) fingerlings

Five isonitrogenous and isocaloric diets containing dietary lipid concentrations from 71.90 to 142.70 g/kg were formulated and fed to Chinese rice field eel Monopterus albus fingerlings (5.00 ± 0.50 g). The highest values of weight gain, specific growth rate (SGR), together with the lowest feed conversion ratio (FCR) were found in fish fed with 89.10 g/kg lipid diet. Fish fed with 71.90 g/kg diet (F1) had higher hepatosomatic index, viscerosomatic index and whole‐body crude lipid than fish in the other four treatments (p < .05). Plasma concentration of triacylglycerol and the activity of alanine aminotransferase were also higher in fish fed with F1 diet. Whole‐body fatty acid profile varied exclusively, but with a stable value of n?3/n?6 ratio. Gas chromatography–mass spectrometry‐based metabolomics identified eighteen differential metabolites (including idose, alanine, glutamic acid, serine and hypotaurine) in liver affected by dietary lipid content using PLS‐DA analysis. The subsequent pathway enrichment revealed ten affected pathways, with the top three pathways being glycine, serine and threonine metabolism; starch and sucrose metabolism; and D‐glutamine and D‐glutamate metabolism. The broken‐line model of SGR suggested that a dietary lipid concentration of 83.50 g/kg was appropriate for M. albus fingerlings.