半滑舌鳎性别特异微卫星标记的SCAR转化及其应用

半滑舌鳎(Cynoglossus semiliaevis)性别控制与全雌育种相关研究需要一种快速、准确的性别特异分子标记。本研究通过对半滑舌鳎共显性性别特异微卫星标记筛选,得到Z、W染色体同源片段相差35bp的位点,对其进行克隆和测序,针对所得测序结果,重新设计引物进行序列特异扩增区间(sequence characterized amplified region,SCAR)转化,增大35 bp差异片段在扩增片段中的所占比例;并摸索得到4%琼脂糖凝胶,150 V,25 min为最适电泳条件,所得SCAR标记可在雌性个体中扩增出169和134 bp两种DNA条带,雄性个体中扩增出169 bp DNA条带,超雌个体中扩增出134 bp DNA条带;将其应用于生产实践中,对半滑舌鳎生理雄性亲鱼576尾进行快速检测,在保证存活的前提下,剔除了亲鱼中的100尾伪雄鱼,有助于提高后代的雌性比例。本研究所得半滑舌鳎性别特异SCAR标记,可用于实验室对半滑舌鳎雌性、雄性和超雌个体遗传性别的准确测定和养殖场简易环境下养殖亲鱼雄鱼中伪雄个体的快速检测。     

半滑舌鳎性别决定的QTL互作研究

半滑舌鳎（Cynoglossus semilaevis）成体雌雄差异较大,性别控制是提高半滑舌鳎养殖效益的有效手段,而实现性别控制的关键在于揭示半滑舌鳎的性别决定的遗传机制。半滑舌鳎的遗传性别决定方式为ZW型,这种性别决定方式可能存在多因子剂量效应,其性别决定不仅与性染色体有关,常染色体也会参与性别调控,遗传性别是性染色体和常染色体的协同作用的结果。本研究从数量性状基因座（quantitative trait loci,QTL）互作的角度来探讨半滑舌鳎遗传性别决定机制,将性别作为二项性状,利用半滑舌鳎高密度微卫星遗传连锁图谱,采用logistic回归模型扫描所有标记间的二阶组合对性别是否存在影响。研究结果发现,共有5个标记组合在P<0.05显著水平上被检测出来,其中组合SCAFFOLD149₇459和SCAFFOLD7854₇1905在P<0.01水平上显著;5个交互组合位于7个常染色体的9个标记当中,这些标记主要集中在连锁群2、10和11,其中连锁群10-11发现了两个差异显著的交互对,且两个交互对均有SCAFFOLD149₇459,说明SCAFFOLD149₇459可能在互作过程中具有较大的影响。研究表明这些标记附近的基因参与了半滑舌鳎的性别决定,也即常染色体可能参与其性别决定的过程,这对进一步研究半滑舌鳎的性别决定和性别控制具有重要意义。     

半滑舌鳎3D-BAC池构建及性别连锁标记的物理定位

半滑舌鳎(Cynoglossus semilaevis)属于雌配子异形染色体性别决定机制(ZW/ZZ),其W染色体包含的大量重复序列阻碍了W染色体序列的精确组装.目前只有物理图谱可以有效地解决由重复序列所造成的组装难题.本研究在已有物理图谱和遗传图谱的基础上,利用3D(three-dimensional)-BAC(bacterial artificial chromosome)池构建和PCR筛选策略进行了性别连锁标记的物理定位.首先将所选44个384孔板的BAC克隆进行接种和预培养,再接种到4个96孔深孔板中.将每两个384孔微孔板的BAC克隆分别汇集获得相应的板池、行池和列池,在提取DNA后,再将相应板池的部分DNA混合得到超级池.最终构建的3D-BAC池,共包括22个超级池和440个基池,覆盖半滑舌鳎基因组4.2倍,完成一个阳性超级池的基池筛选只需24个反应(20个BAC基池和4个对照).然后选用159个半滑舌鳎性别连锁标记对这些克隆池进行两步PCR筛选.在对超级池的筛选中,有142个标记获得阳性扩增.对这些阳性超级池进行基池筛选后,最终有100个标记得到准确定位.定位到半滑舌鳎物理图谱的84个重叠群(contigs)和20个单个克隆(singletons)上,共计1 760个克隆,包含有21 927个共享条带,物理长度为42.4Mb,覆盖半滑舌鳎基因组约5.3％;确定一个定位关系(contig与标记之间的)平均使用了2.2个克隆.在这些标记中,有17个同时定位到了两个或两个以上的contigs上,有11个标记同时定位到contigs和singletons上.另外有19个contigs定位了2个或2个以上标记.这些性别连锁标记的物理定位将有助于半滑舌鳎性染色体基因组序列的精确组装.     

快速鉴定主要禽类性别的一对新的通用引物

家禽的性别一般可以通过翻肛法或其他常规方法进行。翻肛方法对个体的应激较大,而且鹅、鸽等家禽进行翻肛鉴定错误率较高。本研究针对禽类性染色体上的染色质解螺旋蛋白DNA结合蛋白1(chromodomain helicase DNA binding protein 1,CHD1)基因,设计了一对引物g CHD,对鸡(Gallus gallus)、鸭(Anas platyrhynchos)、鹅(Anser anser)和鸽(Columba livia)的性染色体CHD1基因进行PCR扩增。扩增结果显示,雄性禽类只有一条带,雌性禽类有两条带,其中较长的带与雄性的条带位置相同。对扩增产物进行克隆测序,序列分析结果表明,较长的条带序列位于Z染色体,命名为CHD1-Z条带;较短的条带序列位于W染色体,命名为CHD1-W带。在鉴定的4个禽类物种中,CHD1-Z条带与CHD1-W条带大小相差均为150 bp左右,其缺失的序列位于内含子中。结果表明,设计的g CHD引物可以作为禽类的通用引物,通过扩增产物凝胶电泳后的条带数目可快速、准确地鉴定禽类的性别。该方法可以提前鉴定出禽类的性别,提高养殖效率;而且为特定性别的胚胎研究提供了可靠的性别鉴定手段。     

蛋鸽早期性别DNA分子鉴定

蛋鸽早期性别的鉴定一直是制约蛋鸽业发展的瓶颈问题。在本研究中,我们采用PCR扩增和琼脂糖凝胶电泳检测的方法,对20日龄期的100只蛋鸽的性别连锁基因染色体解旋酶DNA结合基因CHD（chromo-helicase DNA binding）进行跨内含子扩增检测。蛋鸽早期DNA分子电泳检测结果与成年后的真实性别核对结果表明：所有雌性蛋鸽扩增结果含有两条带,其大小分别为280bp和250bp,雄性蛋鸽仅有一条280bp的条带;泊松统计分析发现,蛋鸽早期DNA分子判定结果达到统计学上显著水平,可以作为蛋鸽早期性别鉴定的一种方法。本实验实现了以DNA分子为基础的早期蛋鸽性别鉴定,将对蛋鸽业早期的饲养成本降低和早期雄性蛋鸽的淘汰起到准确的指导作用。     

利用羽毛对鸽子进行分子性别鉴定

鸽子是一种单态鸟,并且是典型的"一夫一妻制",给配对和人工繁殖带来了很大的困难.以雏鸽(Columbalivia Gmelin)的羽毛为材料,采用PCR方法扩增染色体螺旋蛋白基因.结果显示,雏鸽羽毛可以提取出高质量的DNA,雄鸽仅有CHD-Z(450 bp)1条带,而雌鸽有CHD-W(380 bp)和CHD-Z(450 bp)2条带.这种性别鉴定技术准确,并且对动物无伤害性,在生产管理上有广阔的应用前景.     

应用牙釉蛋白(AML)基因鉴别牛早期胚胎性别

牛牙釉蛋白（AML）基因定位于牛X染色体和Y染色体上的同源区域.实验根据牛X、Y染色体AML基因第五内含子上序列同源性只有45.1%以及X、Y染色体该区段之间存在多处碱基缺失的特点,合成了1对性别特异性引物.该引物经扩增后母牛只得到1条467 bp的来自X染色体的扩增条带,而公牛能得到1条源自X染色体的467bp片段的扩增条带和1条源自Y染色体的341 bp的扩增条带.经基因组DNA验证,该引物的公母鉴定准确率为100%,同时该对引物具有高度的牛特异性.定量分析AML基因引物的反应灵敏度,发现1次PCR（30个循环）能扩增出0.5ng的基因组DNA,2次PCR（共50个循环）能扩增出20pg的基因组DNA.将AML基因引物与SRY基因引物的反应灵敏度相比较,结果表明前者的灵敏度比后者的高8～10倍.用AML基因反应体系鉴定了26枚优质胚胎,其中24枚有扩增结果,13枚鉴定为公牛,11枚鉴定为母牛.     

半滑舌鳎trim36基因cDNA克隆及表达分析

三重基序蛋白(the tripartite motif-containing protein,TRIM)家族是一类结构保守、进化快速的E3泛素蛋白连接酶,参与诸多重要的生命过程.TRIM36是TRIM家族的一员,trim36编码E3泛素蛋白连接酶.本研究在已完成的半滑舌鳎(Cynoglossus semilaevis)全基因组测序及转录组测序的基础上,利用RACE技术克隆得到半滑舌鳎trim36基因(GenBank登录号:KU244470),序列全长为2 899 bp,其中ORF为2 214 bp,编码737个氨基酸,5’非翻译区(untranslated regions,UTR)为289 bp,3'UTR为396 bp.生物信息学分析显示,半滑舌鳎TRIM36蛋白包含1个锌指结构,2个B-BOX类型锌指蛋白结构域(B-Box-typezinc finger,BBOX),1个卷曲螺旋结构,1个羧基末端的纤连蛋白Ⅲ(fibronectin typeⅢ,FN3)结构域和1个双特异性蛋白激酶spla和兰尼碱受体(spla kinase and ryanodine receptor,SPRY)结构域.此外,在不同脊椎动物中,trim36基因与其邻近的基因具有保守的共线性关系.半定量RT-PCR及qRT-PCR结果显示,在半滑舌鳎不同组织中,trim36基因表达存在差异.trim36在卵巢中表达量最高,其次为雌、雄鱼的脑中;不同发育时期中,trim36基因在120日龄半滑舌鳎性腺中开始表达,且卵巢表达量显著高于精巢(P＜0.05).原位杂交结果显示,trim36基因杂交信号主要出现在Ⅰ期和Ⅱ期卵母细胞.trim36时空表达特征表明,其在卵巢腔的形成及Ⅰ期、Ⅱ期卵母细胞的形成中起重要作用.结果表明,trim36在性别发生方面有一定的作用,这为进一步研究鱼类ttim36基因功能及TRIM家族基因功能提供线索和参考.     

鸡性别决定与分化分子机制研究进展

鸡(Gallus gallus)是重要的模式生物和农业动物,性别是其主要的生长发育性状和经济性状.目前鸡性别决定和分化的分子机制还不十分清楚.已有研究证明,尽管鸡有明确分化的性染色体(ZZ/ZW),性别决定和分化主要由遗传决定,但其性腺和成体性别形成和分化一定程度受到环境因素,特别是机体性激素的调控和影响.此前对鸡性别决定和分化机制的解释,主要集中在W染色体显性效应与Z染色体剂量效应两个假说,分别有一定实验证据支持但都不能令人完全信服.本研究在阐述已有假说及其相关研究的基础上,重点介绍了表观遗传学在鸡性别决定和分化研究中取得的最新进展,以及新近发现的鸡性别决定的细胞自主性问题.     

泰国产方斑东风螺养殖群体遗传多样性的RAPD分析

用随机扩增多态性DNA(RAPD)技术对泰国产方斑东风螺养殖群体的遗传多样性进行检测,从100个随机引物中筛选出21个引物对方斑东风螺的DNA进行扩增,结果表明:21个引物共检测到222条清晰且重复性好的条带,每个引物可扩增出4~16条带,分子量在200~2200bp之间,其中多态位点为156个,占70.27%;群体的Shannon多样性指数为0.2818,Nei基因多样性指数为0.2491;个体间最大遗传距离为0.291,最小遗传距离为0.066。通过与其他贝类遗传多样性的研究结果比较,可初步判断泰国产方斑东风螺养殖群体的遗传多样性比较丰富。     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

Enhanced establishment and growth of giant cardon cactus in an eroded field in the Sonoran Desert using native legume trees as nurse plants aided by plant growth-promoting microorganisms and compost

To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB; the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants, no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi, enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant. In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after 30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as compost or PGPB can either amplify the effect or else attenuate it.     

Karyotypic and genome size variation in Cajanus cajan (L.) Millsp. (pigeonpea) and some wild relatives

Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value.     

Effect of some fungicide seed treatments on the survival of Bradyrhizobium japonicum and on the nodulation and yield of soybean [Glycine max. (L) Merr.]

Several commercial fungicide seed treatments were evaluated for their possible effect on the survival of Bradyrhizobium japonicum on seeds and on the nodulation and yield of soybeans in a greenhouse and a field experiment. quinolate Pro (carbendazim and oxine copper), Vitavax 200FF (carboxin and thiram), and Monceren (pencycuron) had a small effect or no effect on the survival of B. japonicum and on the nodulation and yield of soybeans. They can thus be considered compatible with soybean seed inoculation. Germipro UFB (carbendazim and iprodione), Apron 35J (metalaxyl), and Tachigaren (hymexazol) decreased B. japonicum survival and the nodulation and yield of soybeans and thus cannot be considered compatible with soybean seed inoculation.     

Einfluss der düngungsmethoden auf die entwicklung von zuckerrübenkrankheiten

Während neunjähriger (1994-2002) Untersuchungen in der Versuchsanstalt Ba?cyny (Fahlerde, Fall-Gleyboden, ausgebildet aus leichtem Lehmboden) wurde der Befall mit Krankheiten an der Zuckerrübe in Abhängigkeit von der Düngungsmethode bewertet. Folgende Methoden wurden angewendet: A - Mineraldünger, B - Stalldung und Mineraldünger, C - Stroh-, Gründung und Mineraldünger, D - Kompostdünger und Biopräparate (ökologische Düngung). Auf den Objekten A, B, C wurden bei konstanter Phosphor-Kalium-Düngung die Stickstoffgaben von 0 bis 180 kg.ha^?1 differenziert. Auf dem ökologischen Objekt D ohne Mineraldünger wurden statt Stickstoff die Biopräparate P₅₀₀ und P₅₀₁ verabreicht. Der geringste Befall von Krankheiten wurde an der Zuckerrübe auf jenem Objekt festgestellt, das mit Kompost und den Biopräparaten gedüngt worden war. Im Rahmen der konventionellen Düngungsmethoden wurde allgemein die höchste Intensität der Krankheiten an der mit Stroh, Gründung und Mineraldünger gedüngten Zuckerrübe beobachtet. Ausnahmen von dieser Regel bildete das Vorkommen von echtem Mehltau und Keimlingsfäule. Auf den Objekten A, B, C nahm die Intensität der Krankheiten mit der Steigerung der Stickstoffgabe zu. Auch die auf Objekt D verabreichten Biopräparate stimulierten die Entwicklung der Krankheiten. The effect of various fertilization methods on the diseases of sugar beet was estimated on the basis of nine-year studies (1994-2002) conducted in the Experimental Production Farm in Ba?cyny on loess-based, sedimentary-gley, light-clay soil. The following fertilization methods were applied: A - mineral fertilization, B - mineral and manure fertilization, C - straw, green manure and mineral fertilization, D - ecological compost and biodynamic preparations fertilization. In the objects A, B and C fertilized with phosphorus and potassium, various doses of nitrogen ranging from 0 to 180 kg/ha^?1 were used. In the ecological object D, where mineral fertilization was not used, biodynamic preparations P₅₀₀ and P₅₀₁ were applied instead of nitrogen. The lowest ratio of the diseases of sugar beet was observed in the object fertilized with the compost and biodynamic preparations. In view of the conventional fertilization methods, generally the highest incidence of diseases was noted in the sugar beet fertilized with straw, green manure and mineral fertilizers. The exception was the occurrence of powdery mildew and the black leg. In objects A, B and C the incidence of the diseases increased with the increase in nitrogen doses. The applied biodynamical preparations in the object D stimulated the development of diseases too.     

Prospects for control of Pythium damping-off of lettuce with Trichoderma,Gliocladium and Enterobacter spp.

Summary Damping-off of lettuce (Lactuca sativa) caused by Pythium ultimum was studied in pots containing a non-sterile potting mix in the glasshouse. Fifty P. ultimum sporangia g^-1 compost reduced the plant stand to 15% and shoot dry weight to 18%, but this reduction was totally prevented by applying Trichoderma harzianum at 2×10⁵ viable propagules g^-1 potting mix. Gliocladium virens and Enterobacter cloacae also alleviated the damping-off. E. cloacae did not adversely affect the action of the fungal antagonists. The co-existence of the bacterial and fungal antagonists was revealed on the root surface and inner surface of the testa by scanning electron microscopy, indicating the compatibility of the biocontrol agents.     

细菌、真菌及植物氮营养信号研究进展

氮素吸收代谢是所有生物生命活动的核心部分,因此,各种生物对氮的吸收与同化过程都有精细的调节。这种调节依赖于生物对体内氮素状况信号及体外（生长介质中）氮素信号的感受。过去几十年中,在细菌、真菌中已经对氮素营养信号有了较好的研究,而植物中则相对缓慢,但也有了一定的认识。本文重点比较细菌、真菌及植物中氮信号系统的组成,以期为进一步认识植物中的氮信号接受与转导系统提供启示。     

Potential of wild species for genetic enhancement of some semi-arid food crops

Discovery and incorporation of genes from wild species provide means to sustain crop improvement, particularly when levels of resistance in the cultigens are low and virulent strains of pests and pathogens overcome the host plant resistance. The extent of utilization and the potential of the wild genepool for genetic enhancement were reviewed in five important food crops viz. sorghum, pearl millet, chickpea, pigeonpea and groundnut grown in the semi-arid tropics. Introgression from compatible wild germplasm in the primary gene pool resulted in transfer of new cytoplasmic male sterility systems in pearl millet and pigeonpea, development of high protein, cleistogamous flower and dwarf pigeonpea lines and foliar disease resistant groundnut cultivars. Utilization of wild species in secondary and tertiary gene pools has been generally limited due to sterility, restricted recombination or cross incompatibility. Nevertheless, these species are extremely important as they contain high levels of resistance to several important biotic and abiotic stresses. Several of them, like those belonging to the Parasorghum section and the rhizomatous Arachis species are sources of multiple resistances and hold great promise to sustain crop productivity.     

“绿色革命”以来大气CO2浓度升高对C3作物营养品质的影响

自20世纪60年代"绿色革命"以来,育种技术和农耕技术的发展促进了农作物产量的大幅提升,然而作物的营养品质出现下降趋势。在相似的遗传背景下,大气CO_2浓度升高会使单位体积农作物产品的营养元素含量下降,因此"绿色革命"至今,农作物产品的营养元素下降可能受大气CO_2浓度升高影响。通过植物生长箱模拟"绿色革命"初期和目前的大气CO_2浓度水平(310μmol/mol和400μmol/mol),针对主要C_3作物水稻、小麦和大豆,研究"绿色革命"以来大气CO_2浓度升高对其籽粒的C、N、Fe、Zn元素含量的影响,结果表明:CO_2浓度升高对3种作物籽粒的C元素含量几乎没有影响,变化幅度在±1.5%之间;籽粒的N、Fe、Zn元素含量普遍呈现下降趋势,但均未达到显著水平。