子叶

Cruciferous plants are very important in economic value and theoretical research among the dicots.

十字花科是双子叶植物中一个既有重要经济价值又有理论研究意义的科。

Seeds small, obovate, angular and wingless or planoconvex with a narrow marginal wing; testa crustaceous, shiny; embryo small, straight; cotyledons subrounded, clasping, embedded in copious fleshy endosperm.

种子小，倒卵形，具角和无翼的或平凸具一个狭窄的边缘的翅；种皮壳质，发亮；胚小，直；子叶近圆形，抱茎，嵌入大量肉质胚乳中。

Seeds usually 3-angled; testa thin, crustaceous, smooth to reticulate or verruculose, sometimes adaxially invaginated at hilum; endosperm copious; embryo straight to distinctly curved, lacking chlorophyll; cotyledons broader and much longer than radical.

种子通常3倾斜；种皮薄，壳质，平滑到网状或者小瘤状，有时正面在种脐凹入；胚乳丰富；胚直或明显弯曲，缺乏叶绿素；子叶较宽，远长于胚根。

Fruit a pome, globose, ovoid, or ellipsoid, somewhat fleshy,(1- or)2–5-loculed, free from calyx only near apex or to 1/3 length, with persistent, incurved sepals; carpel crustaceous or membranous, each locule 1- or 2-seeded; seeds erect, testa leathery; cotyledons plano-convex.

果一梨果，球状，卵球形，或椭圆形，稍肉质，(1-或)2-5室，心皮壳质的或膜质，每子房室1或2种子；种子直立，种皮革质；子叶平凸。

Fruit a pome, ovoid to subglobose, fleshy, with persistent sepals; carpel crustaceous; locules abaxially loculicidally dehiscent; seeds oblong, compressed, testa leathery; cotyledons nearly flat.

果一梨果，卵形到近球形，肉质，具宿存萼片；心皮壳质；子房室背面的室背开裂；种子长圆形，压扁，革质；子叶差不多平。

Using nuclear DNA C-values for 539 angiosperms in China, we examined the variation of these values among growth forms and taxonomic groups and the relationship of these values with invasiveness. Mean DNA C-value of the 539 angiosperm species was 4.06 pg. Mean DNA C-value was(1) significantly lower for woody species (1.84 pg) than for herbaceous species(5.02 pg);(2) significantly lower for 360 dicots (2.20 pg) than for 179 monocots (7.80 pg);(3) significantly lower for annuals (2.78 pg) than for perennials(6.65 pg);(4) significantly lower for 134 weed species (1.93 pg) than for herbaceous non-weeds (6.75 pg) and for several families that have an unusually high proportion of weed species;(5) significantly lower for 47 exotic weed species (1.76 pg) than for 134 native weeds (1.93 pg), but significantly lower than that of "non-weedy" herbaceous species (6.75 pg);(6) lower for weeds than for "non-weedy" species in same genus or family; and (7) in herbaceous species, generally lower for weedy compared to "non-weedy" species, with some exceptions such as Avena fatua, whose DNA C-value is as high as 14.15 pg, contrarily, and some "non-weedy" herbaceous species in Cruciferae and Cucurbitaceae with very low values.

统计了中国境内有分布的539种被子植物的DNA C-值，分析了它们在不同分类群、生活型、倍性、生活史类型以及在杂草和非杂草类群中的分布情况，主要结果如下：(1)539种被子植物DNA C-值平均为4.06 pg，其中木本植物的DNA C-值平均为1.84 pg，低于草本植物的平均值(5.02 pg)；(2)双子叶植物(360种)的DNA C-值平均为2.20 pg，极明显地小于单子叶植物(179种)的平均值(7.80 pg)；(3)1年生植物的DNA C-值平均为2.78 pg，明显小于多年植物的平均DNA C-值(6.65 pg)；(4)134种杂草的DNA C-值平均为1.93 pg，明显小于非杂草草本植物的平均值(6.75 pg)，含杂草较多的科，平均DNA C-值相对较小；(5)统计的47种入侵杂草的DNA C-值平均为1.76 pg，略小于134种杂草的平均DNA C-值(1.93 pg)，极显著地小于非杂草性草本植物(6.75 pg)；(6)以科为单位，不同科的DNA C-值存在着极大的差异；(7)DNA C-值与染色体倍性的关系并不明显，但是，随着倍性的增加，基因组变小；(8)在同一科、属中，与非杂草相比，典型杂草的DNA C-值往往偏小；(9)总体上杂草或杂草性强的植物，它们的DNA C-值比非杂草性植物的要小。

The medium water stress in short-term could promote Pn and improve water utility efficiency, but the effect on Pn of Cynanchum komarovii under powerful water stress was marked.

中度土壤水分胁迫在短期内对牛心朴子叶片光合作用具有促进作用，而且有利于WUE的提高。

SQUA genes of Dendrocalamus latiflorus were sequenced, and phylogenetic form on SQUA genes in angiosperms was analyzed. Relative rate and adaptive evolution after SQUA gene duplication in recent common ancestor of monocots and eudicots were analyzed using the methods of relative rate test, statistic on synonymous and non-synonymous coden substitution sites and likelihood rate test.

测定了麻竹的SQUA基因序列并分析了被子植物中SOUA类基因的系统发育式样；采用相对速率检验、同义与非同义置换位点统计以及似然比检验方法，分析了单子叶和真双子叶植物最近共同祖先中SQUA基因发生基因重复后的进化速率与适应机制。

Fruit drupaceous, or nearly a nutlet, often with headlike, wax-covered papillae; endocarp hard. Seeds nearly without endosperm; embryo straight; cotyledons fleshy, plano-convex.

果通常为核果，或者近小坚果，通常带有乳头状的蜡质凸起；内果皮硬种子近没有胚乳；胚直立；子叶肉质，平凸。

OBJECTIVE Study on the chemical constituents of the leaves of Elaeagnus pungens Thunb.

目的 研究胡颓子叶的化学成分。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。