大叶藻胚的石蜡切片制作方法

研究固定方法、脱水及浸蜡时间、染色方式对大叶藻胚石蜡切片制作效果的影响。结果表明,采用标准固定液（FAA）固定48 h以上,脱水每级梯度时间2 h,分3次浸蜡（每次30 m in）,苏木精-伊红染色,可制作出染色清晰、组织结构完整的大叶藻胚切片。     

大叶藻组织培养中外植体消毒方法的研究

为探寻大叶藻组织培养中外植体的最佳消毒方法,采用75%乙醇、1.5%碘化钾、4%次氯酸钠和10%双氧水这4种消毒剂以及不同的处理时间组合,对大叶藻种子和幼苗进行消毒试验。试验结果,最有效的外植体消毒方法为：对大叶藻幼苗,先用无菌水冲洗3~4次,再以75%乙醇处理20 s,然后再用无菌水冲洗3~4次,可以达到较好的消毒效果。对大叶藻种子,先以75%乙醇处理10 min,再以1.5%碘化钾处理10 min,然后用无菌海水冲洗3~4次,这样消毒效果最佳,且不影响种子的发芽率。     

冬季大叶藻与幼参混养效果的模拟研究

在实验室条件下对冬季大叶藻Zosteramarina与刺参却ostichopttsjaponicas当年生幼苗的生态混养效果进行了研究,分析了大叶藻对养殖水体中氨氮、硝酸盐、亚硝酸盐、磷酸盐的控制作用以及大叶藻对幼参生长的集聚效果。试验设置大叶藻与幼参混养组、幼参单养组和大叶藻单养空白组,每组设5个重复。试验幼参为2010年培育的秋苗（体长2．90cm±0．04cm,体质量0．69g±0．02g）,试验总水体75L,幼参放养密度为1个／L,水温为（15±1）℃,盐度为31～32,光照强度为（271±14）lx,试验共进行30d。结果表明：大叶藻单养组氨氮、硝酸盐、亚硝酸盐、磷酸盐含量最高;幼参摄食大叶藻碎屑,对水体营养盐起到一定的控制作用,混养组各种营养盐含量居中;幼参单养组各种营养盐含量最低。试验期间,底质情况良好,水质对幼参的生长无影响;大叶藻可为幼参提供附着基,对幼参的集聚效果良好,超过80％的幼参栖息在大叶藻叶片上。     

MS培养基中氮、磷无机盐对鳗草克隆幼苗生存的影响

为了探究MS培养基中氮、磷无机营养盐对鳗草生长的影响。单独添加不同浓度KNO₃、NH₄NO₃和KH₂PO₄的天然海水中培养鳗草克隆苗,于7、14天进行植株形态学观察和叶片叶绿素含量测定。其中,KNO₃的添加量为MS培养基中的1/2倍、1倍和2倍及NO₃^-总浓度为39.4 mmol/L,KH₂PO₄和NH₄NO₃的添加量均为MS培养基中各自浓度的1/2、1和2倍。结果表明,叶绿素含量以KNO₃处理组最高(P<0.05),克隆苗培养14天无毒害现象,且有新叶发出;NH₄NO₃和KH₂PO₄处理组均对克隆苗有明显毒害作用,NH₄NO₃处理组叶片48 h后开始褐化,7天后茎尖、根尖明显变软并褐化,14天后植株死亡;KH₂PO₄处理组培养14天后叶片平均褐化率达56%。因此,1/2、MS培养基均不适用于鳗草的室内培养,其培养基的氮源应为单独添加的NO₃^--N或高浓度NO₃^--N+低浓度NH₄⁺-N。     

底质与水深对大叶藻和丛生大叶藻分布的影响

考察了烟台玉岱山、担子岛和荣成褚岛海域106个采样点的大叶藻种类的分布及各采样点不同表层底质（深度3 cm以内）、根部底质（深度3～15 cm）和水深等级。对不同底质与水深条件下大叶藻Zostera marina和丛生大叶藻Z.caespitosa的出现频率进行χ2检验。结果表明：不同大叶藻的分布与表层底质、根部底质变化呈极显著相关关系（P〈0.01）,列联系数分别为0.612和0.640;与水深等级变化的相关性虽然显著,但列联系数仅为0.338。在表层底质、根部底质和水深等级3种因素中,两物种的分布与根部底质类型相关性最大,与表层底质类型相关性次之。研究表明,两种大叶藻在不同底质上分布的差异明显,大叶藻偏好泥与泥沙底质,而丛生大叶藻偏好沙与砾石底质。     

水稻和小麦根际的联合固氮作用

本文阐述了水稻和小麦根际的联合固氮作用的测定方法和联合固氮量。通常认为,     

Crustal Spreading in Southern California: The Imperial Valley and the Gulf of California formed by the rifting apart of a continental plate

The current excitement among geologists and geophysicists stemming from the "new global tectonics" has led to a widespread, speculative reinterpretation of continental geology. The Gulf of California and its continuation into the Imperial Valley provide an excellent opportunity for studying the border zone between the North American and Pacific plates, and an interface of continental and oceanic tectonics. The Salton trough, the landward extension of the gulf, is a broad structural depression, comparable in size with the deeper marine basins of the southern part of the gulf, but here partially filled with sediments deposited by the Colorado River.     

加利福尼亚湾茎柔鱼(Dosidicus gigas)渔场声学调查方法

声学方法已成为海洋生物资源评估的重要手段,水声学调查与数据分析作为海洋生物资源声学评估的关键,直接影响渔业资源评估结果.通过对数据处理过程中的目标强度、噪声剔除、物种判别问题进行分析,探究墨西哥加利福尼亚湾的茎柔鱼(Dosidicus gigas)资源水声学调查方法,进而为系统了解和掌握加利福尼亚湾渔场经济品种的资源量...     

千金子和稗草营养器官的解剖学比较

采用常规石蜡切片法，对稻田恶性杂草千金子和稗草营养器官进行了解剖学的观察与比较。结果表明：千金子和稗草的根都有大的辐射状气腔；千金子的茎厚壁组织较少，绿色薄壁组织发达，有髓腔，而稗草茎厚壁组织发达，无绿色薄壁组织，髓细胞破碎而残留部分壁；千金子和稗草都为C4植物，但叶片结构差异较大，千金子的叶片表皮刚毛壁比稗草的壁厚而大，泡状细胞及其分布面积比稗草的小，泡状细胞壁薄，维管束鞘细胞叶绿体较稗草的大，染色深。     

Apospory in Sorghum bicolor (L.) Moench

A line of Sorghum bicolor (L.) Moench was discovered to reproduce by apospory, a type of apomixis. The formation of an embryo by a nucellar cell without fertilization was establshed by cytological observations of ovaries and by progeny tests.     

菠萝黑心病研究进展

综述了菠萝黑心病的研究现状.菠萝黑心病的主要特征是菠萝果实果内褐变,酚类化合物、酶类、活性氧是褐变的发生必须具备的3个因素目前认为该病是受多种因素影响的一种复杂生理变化过程的病害.根据当前菠萝生产和保鲜情况,提出控制菠萝黑心病的途径.     

甘薯天蛾的生物学特性

为明确甘薯天蛾的生物学特性,通过室内饲养及野外调查,研究了温度对甘薯天蛾日Herse convolvuli (L.)生长发育的影响、发育起点温度、有效积温、年生活史以及幼虫取食量、幼虫体色分化、成虫产卵前期和产卵量等生物学特性.结果表明,甘薯天蛾在长沙地区每年发生4代;幼虫共5龄;各虫态的发育起点温度分别为卵10.8℃、1龄幼虫20.7℃、2龄幼虫13.6℃、3龄幼虫14.3℃、4龄幼虫13.1℃、5龄幼虫12.9℃、蛹7.8℃,有效积温分别为45.1日.度、11.2日.度、32.7日.度、32.8日.度、36.6日.度、111.3日.度、252.1日.度;每雌产卵量43～665粒,平均276粒;产卵期2～6d,产卵前期2～5d;适宜交配和产卵的温度是23～30℃.由上述结果可知:光照强度是导致幼虫体色分化的主要原因.     

二穗短柄草Bd21的形态学观察

二穗短柄草（Brachypodium distachyon （L.） Beauv）属于早熟禾亚科。Bd21作为二穗短柄草不同生态型中的一种,在个体大小、基因组大小、生长条件和生长周期等方面与拟南芥类似,并且具有禾本科植物许多共性,如抗病性、颖果等。Bd21的这些特点说明它是一种合适的禾本科模式植物。采用土培和水培的方法观察二穗短柄草的生长特性,利用扫描电镜观察生长锥的发育情况,结果为进一步研究二穗短柄草发育的分子机理提供重要依据。     

Identification of QTLs for Starch Content in Sweetpotato(Ipomoea batatas(L.) Lam.)

Sweetpotato（Ipomoea batatas（L.）Lam.）breeding is challenging due to its genetic complexity.In the present study,interval mapping（IM）and multiple quantitative trait locus（QTL）model（MQM）analysis were used to identify QTLs for starch content with a mapping population consisting of 202 F1 individuals of a cross between Xushu 18,a cultivar susceptible to stem nematodes,with high yield and moderate starch,and Xu 781,which is resistant to stem nematodes,has low yield and high starch content.Six QTLs for starch content were mapped on six linkage groups of the Xu 781 map,explaining 9.1-38.8%of the variation.Especially,one of them,DMFN₄,accounted for 38.8%of starch content variation,which is the QTL that explains the highest phenotypic variation detected to date in sweetpotato.All of the six QTLs had a positive effect on the variation of the starch content,which indicated the inheritance derived from the parent Xu 781.Two QTLs for starch content were detected on two linkage groups of the Xushu 18 map,explaining 14.3 and 16.1%of the variation,respectively.They had a negative effect on the variation,indicating the inheritance derived from Xu 781.Seven of eight QTLs were co-localized with a single marker.This is the first report on the development of QTLs co-localized with a single marker in sweetpotato.These QTLs and their co-localized markers may be used in marker-assisted breeding for the starch content of sweetpotato.     

Identification of QTLs for Starch Content in Sweetpotato （Ipomoea batatas （L.） Lam.）

Sweetpotato （Ipomoea batatas （L.） Lam.） breeding is challenging due to its genetic complexity. In the present study, interval mapping （IM） and multiple quantitative trait locus （QTL） model （MQM） analysis were used to identify QTLs for starch content with a mapping population consisting of 202 F1 individuals of a cross between Xushu 18, a cultivar susceptible to stem nematodes, with high yield and moderate starch, and Xu 781, which is resistant to stem nematodes, has low yield and high starch content. Six QTLs for starch content were mapped on six linkage groups of the Xu 781 map, explaining 9.1-38.8% of the variation. Especially, one of them, DMFN 4, accounted for 38.8% of starch content variation, which is the QTL that explains the highest phenotypic variation detected to date in sweetpotato. All of the six QTLs had a positive effect on the variation of the starch content, which indicated the inheritance derived from the parent Xu 781. Two QTLs for starch content were detected on two linkage groups of the Xushu 18 map, explaining 14.3 and 16.1% of the variation, respectively. They had a negative effect on the variation, indicating the inheritance derived from Xu 781. Seven of eight QTLs were co-localized with a single marker. This is the first report on the development of QTLs co-localized with a single marker in sweetpotato. These QTLs and their co-localized markers may be used in marker-assisted breeding for the starch content of sweetpotato.     

大麦×小麦属间可育异质体的形态和细胞学

用大麦×小麦属间杂种F#-1的无性系与作轮回回交亲本的小麦回交,在回交三代一个株系中,获得自交可育异质体小麦。异质体植株表型似父本,与回交亲本“宁7840”相比,具生长优势,早熟,它们的体细胞染色体数2n = 43,花粉母细胞在减数分裂中期Ⅰ出现高频率的二价体和极少的单价本（每花粉母细胞中分别为21和0.32）。异质体小麦并具优良的农艺性状和高的育性,将可能成为一个新的小麦种质。在小麦改良中具有潜在的应用前景。     

水稻亚种间亲和性研究进展

概述了水稻籼粳亚种间亲和性的研究进展,介绍了广亲和概念,广亲和测验种,广亲和基因的遗传研究,新的杂种不育基因的发现及分子定位,以及广亲和系的选育进展等,并就如何利用这些亲和基因进行了讨论。     

SSR fingerprinting of 203 sweetpotato (Ipomoea batatas (L.) Lam.) varieties

Simple sequence repeat (SSR) markers have been shown to be a powerful tool for varieties identification in plants. However, SSR fingerprinting of sweetpotato varieties has been a little reported. In this study, a total of 1294 SSR primer pairs, including 1215 genomic-SSR and 79 expressed sequence tag (EST)-SSR primer pairs, were screened with sweetpotato varieties Zhengshu 20 and Luoxushu 8 and their 2 F₁ individuals randomly sampled, and 273 and 38 of them generated polymorphic bands, respectively. Four genomic-SSR and 3 EST-SSR primer pairs, which showed good polymorphism, were selected to amplify 203 sweetpotato varieties and gave a total of 172 bands, 85 (49.42%) of which were polymorphic. All of the 203 sweetpotato varieties showed unique fingerprint patterns, indicating the utility of SSR markers in variety identification of this crop. Polymorphism information content (PIC) ranged from 0.5824 to 0.9322 with an average of 0.8176. SSR-based genetic distances varied from 0.0118 to 0.6353 with an average of 0.3100 among these varieties. Thus, these sweetpotato varieties exhibited high levels of genetic similarity and had distinct fingerprint profiles. The SSR fingerprints of the 203 sweetpotato varieties have been successfully constructed. The highly polymorphic SSR primer pairs developed in this study have the potential to be used as core primer pairs for variety identification, genetic diversity assessment and linkage map construction in sweetpotato and other plants.