AMF接种与根系分隔对红壤上间作玉米生长及磷素吸收的影响

通过盆栽模拟试验研究比较以Glomus mosseae(GM)和Glomus etunicatum(GE)为接种剂,设置不同根系分隔方式(不分隔,隔尼龙网,隔塑料膜)对间作玉米植株生长及磷素吸收累积的影响。结果表明,两种菌根真菌GM和GE对玉米根系的侵染效果相近,GM为玉米优势丛枝菌根真菌(AMF),接种GM使玉米根长、地上部和根系生物量、地上部和根系磷含量、磷吸收量均显著提高;接种GE显著降低了玉米根冠比、株高和根系磷吸收效率。间作体系不同根系分隔方式对玉米的影响也不同,根系隔尼龙网处理显著降低了玉米根长和根系生物量,显著提高了根系的磷含量;根系隔塑料膜处理对玉米的地上部和根系磷含量、磷吸收量以及根系磷吸收效率均起显著降低作用。所有复合处理中,以GM不分隔处理组合对间作玉米的生长及磷素累积的促进作用最好。     

AMF接种与作物根系分隔方式对紫色土上间作大豆生长及磷素吸收的影响

比较了不同丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)接种状况[不接种(NM)、接种Glomus mosseae(GM)、接种Glomus etunicatum(GE)]和玉米/大豆间作体系不同根系分隔方式(不分隔,隔尼龙网,隔塑料布)对大豆植株生长及磷素吸收累积的影响。结果表明:接种GM和GE处理下的间作大豆根系侵染率在不同根系分隔方式之间无显著差异,接种AMF抑制了间作大豆根系的伸长,其中接种GM处理能使大豆生物量显著提高,并在根系不分隔处理下使大豆对磷素吸收较多而生长较好,接种GE真菌则不能促进大豆对磷素的积累。间作体系不同根系分隔方式对大豆的影响也不同,其中大豆的根系长度在隔塑料布处理下最短,大豆生物量在根系分隔处理下均大于不分隔处理,根系不分隔处理能够较好的促进大豆对磷素的积累。所有复合处理中,以GM-不分隔处理组合对间作大豆的生长及磷素累积的促进作用最好。     

水分胁迫下丛枝菌根真菌对澳洲坚果幼苗磷利用效率的影响

基于云南热区澳洲坚果种植区季节性干旱及先天性低有效磷的土壤特征,探讨丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)接种对具有排根的引种作物-澳洲坚果幼苗磷利用的影响,为外来物种的本地驯化栽培提供理论依据。在正常水分与水分胁迫条件下,对盆栽的澳洲坚果幼苗分别接种土著丛枝菌根真菌(native arbuscular mycorrhizal fungi)和摩西球囊霉(Glomus mosseae),测定接种不同AMF对澳洲坚果幼苗生长、菌根定殖、酸性磷酸酶活性、柠檬酸分泌及磷素吸收等的影响。结果表明,接种土著AMF(N-AM)处理对澳洲坚果幼苗排根或非排根的侵染率显著高于接种摩西球囊霉(G-AM)处理,正常水分条件下N-AM处理的侵染率最高;两种水分条件下,接种AMF的植株地上部和地下部干重更高,正常水分处理下达到最大。菌根侵染率与排根产生量之间显著正相关,水分胁迫显著抑制了植株的排根产生量;与不接种相比,接种处理能显著提高排根产生量。接种AMF后根系对磷素的活化、吸收及转化能力显著升高,表现为接种的澳洲坚果幼苗根系、茎秆和叶片中全磷含量较高,两种水分条件下均表现为N-AM>G-AM>CK;菌根与排根相互协调共同发挥作用,显著改善了澳洲坚果幼苗根系对磷素的活化和吸收能力,且菌根比排根发挥了更大作用,尤其在水分胁迫条件下。两种AMF均能与澳洲坚果幼苗建立共生关系,N-AM处理的幼苗各指标显著优于G-AM处理,可能是由于拥有多样性优势的土著AMF在澳洲坚果幼苗根系中定殖能力较强或是AMF真菌对外来物种澳洲坚果有正反馈作用。     

大豆根系特征与磷素吸收利用的关系

大豆幼苗经过培养处理形成三种内磷浓度,在两种不同营养液磷水平下进行培养,研究大豆根系特征与磷素吸收利用之间的关系.研究发现,大豆植株体内磷对促进根系的伸长有着非常重要的作用.对于相同的内磷处理,不同外源磷对根长影响较大,外磷浓度越高根长越短,尤其在磷处理后的第3周,S2和S3内磷水平的处理,从P2降低到P1水平时,根长分别增加了5.2%和30.1%.在无外磷的条件下,不同内磷浓度对根表面积的影响从磷处理后的第2周开始均达到了5%的显著水平,而施加外磷的处理,只有在磷处理后的第4和第5周,才达到5%的差异显著水平.在所有的取样时期,植株干生物量与磷效率比值没有达到显著水平,但是,随着磷效率比值的增加,达到0.40以后,植株干生物量随着磷效率比值的增加而增加.植株磷效率比值与含磷量之间达到了1%的显著水平,随着磷效率比值的增加,植株体内含磷量呈指数下降.     

槟榔/香草兰间作促进植株氮养分转化与利用

以槟榔与香草兰间作系统为研究对象,探讨氮素养分利用规律。采用盆栽模拟试验,以‘热引3号’香草兰和‘热研1号’槟榔为试验材料,研究槟榔单作、香草兰单作和槟榔间作香草兰3种种植模式,在纯氮112.5、225、300 kg/hm²和不施氮肥4个氮肥处理条件下,对植株生物量、氮素吸收和利用、土壤全氮含量和氮肥利用率的影响。结果表明,随着氮肥施用量的增加,不同种植模式下各施氮处理的植株鲜和干生物量差异显著（P<0.05）,间作模式的植株鲜和干生物量最高,分别比对照增加61.3%、34.9%、43.1%和47.2%、62.7%、33.8%;间作模式的植株全氮含量比单作植株的高0.43~2.63 mg/g;间作模式显著增加了植株的吸氮量,分别比对照增加了40.44、47.79和53.92 kg/hm²;间作模式还显著增加植株的氮吸收效率、氮利用效率和氮肥利用率,但对土壤全氮含量影响不明显。     

全周期胶园间作对豆薯和大豆的产量、品质和土壤速效养分的影响

研究在全周期胶园宽行间作豆薯和大豆的产量、品质和土壤速效养分的影响。结果表明,与单作相比,间作大豆产量显著降低40%(p0.05),间作豆薯产量略低但差异不显著(p0.05)。总体上,单作和间作处理豆薯和大豆不同位置的可溶性糖、淀粉、粗蛋白和粗脂肪的含量没有显著差异(p0.05),但间作提高了间作带中间区域豆薯的粗脂肪含量。单作豆薯和大豆平均土壤铵态氮、硝态氮均显著高于间作处理的不同位置(p0.05);单作豆薯和大豆土壤速效钾含量高于间作处理且显著高于单作小区两侧(p0.05);而单作豆薯和大豆土壤速效磷则低于间作处理,其中单作豆薯显著低于间作豆薯小区中间区域(p0.05)。综上所述,豆薯比大豆更适合间作于全周期胶园,间作对作物的品质总体上没有影响,但对降低土壤无机氮含量较明显。     

低分子量有机酸对大豆根系形态和磷素吸收积累的影响

采用砂培试验研究了几种低分子量有机酸(柠檬酸、草酸、苹果酸和三种酸的混合)对根系形态和磷素吸收积累的影响.结果表明:不同有机酸处理均显著降低了大豆根系生物量和根冠比,同时使根长、根表面积和根体积均显著降低,而且随着有机酸浓度的增加抑制作用加强,几种有机酸混合后,抑制作用也相对增强,表明不同有机酸处理均抑制了大豆根系的生长,同时使大豆根系的竞争能力降低.几种有机酸处理均降低了大豆对磷素的吸收积累,从而降低了大豆对磷素的吸收效率,但磷利用效率增加.     

胡椒与槟榔间作对群体养分吸收利用的影响

选用胡椒与槟榔种子苗为材料,比较胡椒与槟榔间作和二者单作条件下,胡椒与槟榔的根系形态、地上部和根系的养分浓度和含量、养分吸收和利用效率、地上部和根系生物量的差异。结果表明:胡椒与槟榔间作显著提高了胡椒根系有效形态及地上部氮、磷、钾、钙和镁的养分含量,胡椒对磷的利用效率和地上部生物量均表现出明显的间作优势。分析胡椒根系形态参数与养分效率相关关系,发现胡椒的根长密度、比根长和比表面积与磷的利用效率显著正相关,其中比根长对磷利用效率提升的贡献率达94%,胡椒/槟榔体系显著提高了胡椒的这3个根形态参数和生物量,所以,胡椒/槟榔体系通过改变胡椒根系形态,增加了对养分的吸收量和利用效率,从而提升了胡椒的生物量。间作还提高了槟榔根系氮和磷的养分含量,提高了槟榔对氮和磷的利用效率。间作体系中槟榔对氮和磷的利用效率增加,有利于提高槟榔抵抗病虫的能力,还可以改善槟榔黄化现状和防止其发生。可见,间作体系通过改变胡椒和槟榔的根形态,提升了二者对养分的吸收利用效率和胡椒生物量。     

胡椒园间作槟榔对胡椒产量及养分利用的影响

胡椒园间作槟榔是海南胡椒间作体系中应用较广的一种模式,为探明其间作优势来源,以海南胡椒优势种植区4个试验点的胡椒单作与胡椒/槟榔模式为研究对象,调查了2009~2011年各点胡椒产量与养分投入状况,测定2011年土壤养分与胡椒植株叶片养分含量,从而对比了间作模式与胡椒单作模式下胡椒产量、土壤养分状况、肥料产量贡献率和胡椒叶片养分含量的差异。结果表明：在各试验点不同产量水平下,同一地点间作模式的胡椒产量均极显著高于单作。间作模式土壤氮、磷、钾全量含量略低于单作,但未达到显著水平;间作模式土壤速效磷和速效钾含量高于单作,且速效磷差异达到显著水平。在养分投入相同的条件下,间作模式氮、磷、钾肥料偏生产力均极显著高于单作。间作模式下胡椒叶片磷、钾养分含量周年大于单作。上述结果表明胡椒/槟榔间作提高了土壤中速效养分的含量,促进了胡椒对磷、钾等养分的吸收,从而提高了其肥料利用效率,并最终提高胡椒产量。胡椒/槟榔的间作优势可能与二者地下部互作有关。     

槟榔间作香露兜对土壤养分和养分吸收的影响

为了研究槟榔间作香露兜对土壤养分和养分吸收的影响,采用盆栽试验的方法,对槟榔单作、槟榔间作香露兜和香露兜单作3种种植模式的土壤理化性质和养分吸收进行比较研究。结果表明：槟榔间作香露兜后,相对于单作槟榔,土壤EC值和碱解氮含量显著降低47.15%和25.74%,土壤速效磷含量显著增加32.32%,其中碱解氮与过氧化氢酶和过氧化物酶极显著负相关,速效磷与总根长、根系总表面积、根体积、根数目、脲酶和酸性磷酸酶显著正相关,速效磷与过氧化氢酶和过氧化物酶极显著正相关;槟榔地上部N浓度以及香露兜地上部P和K浓度分别显著增加41.56%、26.56%和25.69%;而槟榔和香露兜根系以及地上部N、P和K养分含量均高于单作,其中根系槟榔P和K含量和香露兜K含量显著增加;同时,间作后槟榔和香露兜对N的吸收效率均高于单作,香露兜的P和K的吸收效率高于单作并略高于槟榔的吸收效率,其中P和K的吸收效率与总根长、总表面积、根体积、根数目均显著正相关,氮的吸收效率与根系形态无显著相关关系。综上所述,槟榔间作香露兜增加了土壤中速效磷含量,促进了槟榔和香露兜对氮、磷和钾养分的吸收,土壤速效磷含量的增加、养分吸收效率的提高均与根系形态显著正相关。     

钾素水平对油菜酶活性的影响

利用盆栽试验研究不同钾素施用水平对油菜薹期酶活性的影响。结果表明 ,钾素缺乏和过量均可导致油菜叶片POD含量上升 ,CAT和SOD含量下降。不同施钾水平条件下 ,油菜下部叶的酶活性差异比上部叶更明显     

Haloarchaea as Cell Factories to Produce Bioplastics

Plastic pollution is a worldwide concern causing the death of animals (mainly aquatic fauna) and environmental deterioration. Plastic recycling is, in most cases, difficult or even impossible. For this reason, new research lines are emerging to identify highly biodegradable bioplastics or plastic formulations that are more environmentally friendly than current ones. In this context, microbes, capable of synthesizing bioplastics, were revealed to be good models to design strategies in which microorganisms can be used as cell factories. Recently, special interest has been paid to haloarchaea due to the capability of some species to produce significant concentrations of polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), and polyhydroxyvalerate (PHV) when growing under a specific nutritional status. The growth of those microorganisms at the pilot or industrial scale offers several advantages compared to that of other microbes that are bioplastic producers. This review summarizes the state of the art of bioplastic production and the most recent findings regarding the production of bioplastics by halophilic microorganisms with special emphasis on haloarchaea. Some protocols to produce/analyze bioplastics are highlighted here to shed light on the potential use of haloarchaea at the industrial scale to produce valuable products, thus minimizing environmental pollution by plastics made from petroleum.     

不同杀菌方式对龙眼原汁品质的影响

为了探讨不同杀菌方式在达到商业杀菌要求的基础上对龙眼原汁营养成分及理化性质的影响,以广西南宁地区所产的“石硖”龙眼为原料,对比分析了巴氏杀菌(PS)、微波杀菌(MS)、超高温瞬时杀菌(UHT)和高压脉冲电场杀菌(PEF)4种杀菌方式对龙眼原汁的菌落总数、色差、pH值、可溶性固形物、总酚、糖组分及有机酸等指标的影响。结果表明：4种杀菌方式均能达到商业无菌要求,对龙眼原汁的pH值和葡萄糖含量无显著性影响(p>0.05);与对照组(CK)相比,PEF杀菌对龙眼原汁中L*值、b*值、可溶性固形物(TSS)、果糖、总糖、酒石酸、富马酸含量影响不显著(p>0.05);与PS、MS和UHT杀菌相比,PEF杀菌对龙眼原汁中的总酚、抗坏血酸、总酸的影响幅度较小。因此,PEF杀菌技术不仅具有较好的杀菌效果,而且能更好地保持龙眼汁原有的色泽和营养品质。     

叶面喷施微肥对冬小麦产量和品质的影响

为给小麦高产优质栽培中微肥施用提供参考,以冬小麦品种石新828为材料,研究了叶面喷施锌、铁、硒3种微肥对小麦产量、籽粒锌、铁、硒和蛋白质含量的影响。结果表明,3种微肥中只有喷硒增产作用显著(P<0.05),但喷锌、铁、硒分别显著增加了千粒重、穗数和穗粒数。3种微肥均能明显提高籽粒中相应的微量元素含量,但对籽粒蛋白质含量影响均不显著。     

52个甘蔗品种在广西受病毒侵染情况

为明确国家糖料体系甘蔗集成示范及区试品种在广西被病毒侵染情况,2017年从广西北海、南宁、崇左、百色、来宾、柳城、桂林等地集成示范及区试的52个甘蔗品种上采集带有甘蔗花叶病、甘蔗黄叶病和甘蔗杆状病毒病显著病症或不显病症叶片样品,采用特异引物通过RT-PCR和PCR方法进行5种病毒检测（甘蔗黄叶病毒、甘蔗线条花叶病毒、高粱花叶病毒、甘蔗花叶病毒和甘蔗杆状病毒）。结果表明,SCYLV的平均检出率为25.00%;SCSMV的平均检出率为7.97%;SrMV的平均检出率为7.69%;SCMV的平均检出率最低,为7.42%;SCBV的平均检出率最高,为68.41%,远远高于其他病毒。7个地方的甘蔗受病毒混合侵染现象普遍存在,北海的病毒混合侵染率甚至高于单一病毒侵染率。52个甘蔗品种在广西受5种病毒的总侵染率为79.67%,对甘蔗的生产安全存在着严重的潜在威胁,建议推广种植甘蔗脱毒种苗来缓解甘蔗病毒病害的危害。     

红麻粉蚧虫形态特征的观察

本文描述了危害我国华南留种红麻两种粉蚧:木槿曼粉蚧Maconellicoccushirsutus(Green)、拟葡萄粉蚧PseudococcusViburini(Signoret)的主要形态特征及其差异比较,这对红麻害虫虫种的识别及指导防治具有重要意义。     

Association mapping in rice: basic concepts and perspectives for molecular breeding

In the last decade, association mapping (AM) has become a well-established method to detect genes and quantitative trait loci (QTLs) associated with agronomically important traits. The identification of a large number of single nucleotide polymorphisms (SNPs) from genome sequencing and concurrent development of high-throughput genotyping platforms has led to AM being widely used for a range of crops. These technologies have been used in rice (Oryza sativa) to explore the abundant diversity and there is enormous potential to identify novel QTLs for traits of interest. Due to the availability of cost-effective high-throughput SNP genotyping methods and rapid developments in rice genomics, it is inevitable that these AM approaches will become more popular in the future, especially in the context of genome-wide association studies (GWASs). In this paper, we review the fundamental concepts, critical considerations and limitations of AM focusing on rice, and reiterate the importance of accurate phenotypic data. We also include a section about connecting GWAS to molecular breeding, covering practical consideration for breeders, which is required to use GWAS results in actual rice molecular breeding programs and which has not received adequate attention in the scientific literature.     

利用Affymetrix芯片分析DON诱导抗赤霉病小麦品种望水白的基因表达谱

中国小麦地方品种望水白不但高抗赤霉病,而且其籽粒中DON(脱氧雪腐镰刀菌烯醇,被认为是赤霉病的致病因子)含量也低.为了研究望水白低DON含量的分子机制,利用Affymetrix小麦基因芯片对望水白受DON诱导调控的基因进行高通量的检测,以DON诱导后12 h和24 h混合样品作为处理组,水处理做为对照.总共检测到差异表达的基因1 114个,其中上调表达的基因有949个,下调基因165个.在上调表达基因中,推断有功能的基因涉及转录因子、信号蛋白、着丝粒蛋白以及与病程相关的基因,如:腺苷三磷酸结合盒转运蛋白,谷胱甘酞转移酶、细胞色素P450酶、苯丙氨酸解氨酶、葡萄糖基转移酶以及抗病蛋白等.对上调表达中的部分基因进行RT-PCR分析,证实它们都受DON诱导上调表达,与芯片检测结果吻合.     

Collaborative breeding with farmers can be effective

Plant breeding efficiency is increased by better taking into account the needs of the clients. This can sometimes be helped by involving farmers in selection in the segregating generations. We describe a rice-breeding programme in Nepal where the use of simple breeding methods optimised the benefits from such collaboration. Farmers grew in their fields large populations that were bulks derived from the F₂ generations of single crosses. They selected within them starting in a generation where selfing was sufficiently advanced for the between-plant heritability to be high. Poorer bulks were soon rejected by farmers. A high proportion selected within the bulks and a significant proportion did so over several generations. An increasing number of farmers grew the best of the selected bulks because they spread from farmer to farmer without the need of intervention from scientists. Varieties selected from these bulks were preferred by farmers in on-farm trials and had a superior combination of yield and maturity compared with the later breeders’ selection from the same bulk. Levels of participation were higher with the better performing bulks and even when training was not provided, provided the germplasm performed acceptably well sufficient farmers selected in the bulks to make collaborative breeding cost effective. Collaborative breeding can be successful but demands different types of resources than those for on-station breeding so its cost effectiveness will vary with circumstances. It can be used to increase the probability of selecting segregants that perform well across environments by using methods that pool bulks selected by different farmers and it is also extremely useful for decentralising breeding programmes.     

Light interception and utilization in relay intercrops of wheat and cotton

In China, a large acreage of cultivated land is devoted to relay intercropping of winter wheat and cotton. Wheat is sown in strips with interspersed bare soil in October and harvested in June of the next year, while cotton is sown in the interspersed paths in the wheat crop in April and harvested before the next wheat sowing in October. This paper addresses the question how strip width and number of plant rows per strip of wheat or cotton affect light interception (LI) and light use efficiency (LUE) of both component crops.