Study on the Relationship Between the Ploidy Level of Microspore-Derived Plants and the Number of Chloroplast in Stomatal Guard Cells in Brassica oleracea

The relationship between the ploidy level of microspore-derived plants and chloroplast number in stomatal guard cells was studied in cabbage, broccoli, and Chinese kale. In the experiment, distribution statistics analysis and t-test were used to perform statistical analysis on chloroplast number of different ploidy level in those stomatal guard cells mentioned above, and morphology identifying and chromosome counting were used to test accuracy of counting chloroplast number in stomatal guard cells. The chloroplast average number in stomatal guard cells was very similar among the different leaf positions on the same plant and among significantly among the different ploidy the different locations in the same stoma in the same variety. All the leaf, while the chloroplast number varied distributions of the chloroplast number in different ploidy stoma were normal distribution fitted. A correlation has been established between ploidy and chloroplast number in the stomatal guard cells. In every single stoma of microspore-derived plants, the chloroplast number for a haploid should not be more than 10, diploids 11 to 15, and polyploids more than 15. The accuracy of this method for identification of different ploidy plants was 93.93%. Furthermore, the accuracy of this method was reliable and did not vary with the plants growth conditions. Therefore, the chromosome ploidy of plants derived from microspore culture in cabbage, broccoli, and Chinese kale can be identified by simply counting the chloroplast number in stomatal guard cells.     

Induction and characterization of polyploids from seeds of Rhododendron fortunei Lindl.

Most Rhododendron species are ornamental flowering species widely distributed in Asia, North America, and West Europe. Rhododendron fortunei, one of the endemic Rhododendron species in China, has beautiful flowers with bright colors and is being exploited to meet the needs of the flower market. Polyploid plants usually show superiority in growth, disease resistance, and adaption over their diploid relatives. Here, we report the first case of polyploid induction in R. fortunei. In order to induce polyploidy in R. fortunei, germinating seeds were treated with different concentrations of oryzalin for 16 h. By evaluating ploidy level with flow cytometry, a total of 34 polyploid R. fortunei lines, including 27 tetraploid lines and seven octoploid lines, were obtained. A comparison of treatments indicated that 7.5 mg L–1 oryzalin was the optimal concentration for polyploid induction in seeds of R. fortunei. Compared with diploid plants, tetraploid and octoploid plants exhibited slower growth rates and had thicker and rounder curled leaves with more leaf epidermal hairs. Moreover, larger stomata at lower density were also observed in the leaves of polyploid plants. Chlorophyll contents were also significantly increased in polyploid plants, which leads to a darker green leaf color. Both small and large individuals exhibiting the same characteristics were observed among the obtained tetraploid plants. Overall, our study establishes a feasible method for polyploid induction in R. fortunei, thus providing a basis for breeding new R. fortunei varieties.     

4种不同品种石榴的叶表皮特征电镜扫描观察(英文)

[Objective] The research aimed to provide reference for classification of pomegranate cultivars and studies of genetic relationship among pomegranate cultivars.[Method] The electron microscope scanning was used to comparatively observe leaf epidermal structures of 4 pomegranate cultivars.[Result] The upper epidermal structures of 4 pomegranate cultivars were similar and showed reticular structure .However, the differences existed in lower epidermis,such as cell shape,cell size and arrangement mode of cell as well as stomatal density,while the structures of leaf vein in lower epidermis of 4 pomegranate cultivars were similar.[Conclusion] The research provided morphological references for studying heterosis of pomegranate to some extent.     

Characteristics of Rice Plant with Heavy Panicle

Using 15 indica rice varieties with different panicle weight, some ideal plant type characteristics in heavy panicle type of hybrid rice （HPT） and their relation to yield and its components were studied. Results showed that the leaf area index （LAI） of the HPT varieties was lower than that of medium panicle type （MPT） and light panicle type （LPT） varieties, but its decreasing rate of LAI and efficient LAI after heading was slower and had much higher percentage of efficient LAI, specific leaf weight, and ratio of grain to leaf area （cm^2） in comparison with the MPT and the LPT varieties. The length, width, thickness, and area of top three leaves of the HPT varieties were significantly larger than those of the MPT and the LPT varieties, and these components of top three leaves were significantly and positively correlated with the number of spikelets and filled grains, grain weight per panicle, and grain yield. The flag leaf in HPT varieties was erect with sorrow leaf angle, and their leaf angle of 2nd and 3rd leaf from top increased in sequence. The plant height of the HPT varieties was higher than that of the MPT and the LPT varieties, and their leaf site of top three leaves also increased in sequence. Therefore, HPT varieties as an ideal plant type could increase the utilization efficiency of sunlight energy. The ideal plant type characteristics and their adjuncts for the HPT varieties are proposed in this article.     

Study on Floral and Pollen Characters of Tetraploid Rice

Polyploidization is the evolution trend of many crops, and the yield increased obviously after polyploidization. The polyploidization of rice often brings ＂gigas＂ of both vegetative organs and seeds. Howevere, in rice breeding, it is required for restoring lines to have not only big anthers but also abundant pollens. People often doubt that the enlargement of the floral organ may just be enlargement of cell size in polyploid rice. So, it is of significance to study characteristics of floral organs and pollens of several tetraploid rice varieties or lines. Floral organ and pollen characteristics of Sg99012 and HN2026 were studied comparatively by stages and different ploidy levels, with the materials 9311, HD9802S, and PA64S as the control. The results showed that chromosome doubling had much more influence on floral characteristics of every lines than seeding by stages, and the tetraploids of every lines displayed ＂gigas＂. In correlation analysis, spikelet length, spikelet width, and anther length had significant correlation; spikelet width and anther width had significant correlation, too. Both seeding by stages and chromosome doubling made the correlations of characters between every floral organ changed to some extent. Seeding by stages had little effect on pollen diameter and fertility of HN2026-4X and Sg99012-4X. But chromosome doubling increased pollen size of every lines remarkably, and also increased the pollen quantity of PMeS （polyploid meiosis stability） restoring line HN2026-4X and gene map restoring line 9311-4X remarkably, whereas only had little effect on that of sterile lines. Moreover, chromosome doubling changed pollen fertility and made the number of fertility pollen of 9311 reduced significantly, but the pollen fertility of HN2026 （PMeS restoring line） and PA64S （sterile line） almost had no change after chromosome doubling. The results showed that tetraploid restoring lines had advantage of abundant and big size pollens, and tetraploid sterile lines had the characters of big size pollens, few change of pollen quantity and stable sterile character. These results provided evidence in reproductive biology for utilizing heterosis of polyploid rice by two-line method.     

Analysis of Variations in White-Belly and White-Core Rice Kernels Within a Panicle and the Effect of Panicle Type

This study aims to investigate the variation in occurrence of white-belly rice kernel（WBRK） and white-core rice kernel（WCRK） among different positions within a panicle. Twenty-four M4 mutants involved in four panicle types, namely the compact, intermediate, loose, and chicken foot panicle were used. They derived from a japonica rice cultivar Wuyujing 3. Considerable differences in morphological characters existed among the four types of panicle, especially in panicle length, the secondary branch number and ratio of grain number to total branch length. Marked differences were found in WBRK and WCRK among different positions within a panicle for all types of panicle. In general, grains located on the primary rachis and top rachis branches had higher WBRK and WCRK percentage than those on the secondary rachis and bottom rachis branches. WCRK exhibited larger variation among grain positions than WBRK did. Moreover, there was a significant difference in WCRK/WBRK among grain positions within a panicle, with primary rachis and top rachis branches having higher values than the secondary and bottom rachis. In addition, panicle type showed no significant effect on the pattern of WBRK and WCRK occurrence within a panicle. The results indicated the difference in mechanism of WBRK and WCRK formation in grain position within a panicle, and are valuable for breeding and agronomic practices aimed at lowering chalky grain rate.     

Cytological Evaluation and Karyotype Analysis in Plant Germplasms of Elytngia Desv.

Elytrigia Desv. is widely distributed throughout the world and is represented with species of various levels of ploidy including diploids, tetraploids, hexaploids, octaploids, and decaploids. The distribution pattern of these ploidy levels, however, is not well-defined. In this study, the levels of ploidy for 64 accessions of Elytrigia from 25 countries were determined with microscopic procedures. The results showed that accessions of E. intermedia and E. repens were grouped into three distinct levels of ploidy including diploids, tetraploids and hexaploids. For E. elongata, E. pontica, and E. caespitosa, it was found that two ploidy levels presented, and only one ploidy level was in those of E. hybrid, E. pycnantha, E. pungens, E. juncea, and E. alatavica. Karyotype analysis indicated that the karyotype formula of diploid, tetraploid and hexaploid of E. intermedia was 2n = 2x = 14 = 6m ＋ 6sm ＋ 2st, 2n = 4x = 28 = 2M ＋ 10m ＋ 16sm and 2n = 6x = 42 = 4M ＋ 18m ＋ 20sin, respectively. Furthermore, the karyotype formula of three germplasms in tetraploid of E. intermedia was 2n=4x=28 =2M＋ 10m＋ 16sm, 2n=4x=28=4M＋22m （sat）＋2sm and 2n=4x=28 =4M＋ 12m＋ 12sm （sat）, which were not completely uniform. Therefore, it could be suggested that the studies about chromosome constitution would be helpful for the detail understanding of the diversity of germplasm resource in Elytrigia and promoting the utilization in the crop molecular breeding.     

Obtaining and Cytological Identification of a Set of Primary Trisomics in Cabbage

Selection of primary trisomics of the cabbage （Brassica oleracea var.capitata L） forms an important basis for gene chromosome mapping and for other genetic studies. The cabbage self-fertilization line - 9601 was used as material, using the root-tip cell chromosome number and pollen mother cell chromosome number identification and karyotype analysis to select the primary trisomics from the progenies of 3x x 2x in the cabbage. Many aneuploid plants with one or two extra chromosomes were obtained and a set of primary trisomics （Tri-1, Tri-2, Tri-3, Tri-4, Tri-5, Tri-6, Tri-7, Tri-8, and Tri-9, in which the Tri-1 and Tri-4 were from 2n＋2 plants and others from 2n＋ 1 plants） was acquired from these plants. Each trisomic exhibited some unique features, such as plant height, plant type, leaf type, size of flower bud, and inflorescence. The triploid crossing by the diploid is a convenient and effective way to select trisomics in the cabbage.     

Absorption,Accumulation and Distribution of Zinc in Highly-Yielding Winter Wheat

Zinc（Zn） is an important essential microelement for wheat.In order to study the characteristics of Zn absorption,accumulation and distribution in highly-yielding winter wheat（with a grain yield of 9 000 kg ha-1）,field experiments were conducted in Gaocheng County of Hebei Province,China.Four winter wheat cultivars,i.e.,Shimai 14,Jifeng 703,Shimai 12,and Shixin 828,and four cultivars,i.e.,Temai 1,Shimai 12,Shixin 531,and Shixin 828,were used in the experiment,during 2004-2005 and 2005-2006,respectively.Plant samples were taken from the plots at each growing stage for Zn concentration analysis.The main results showed that the concentration of Zn in various above-ground organs of wheat was 9.5-112.5 mg kg-1 at different growing stages.The organ with the highest Zn concentration differed with the change of growth center at different growing stages.Accumulation of Zn in leaf blades was the highest among all the organs during early growing period,and more than 50% of the Zn accumulation was distributed to leaf blades before jointing,and higher than that to other organs.In late growing period,however,the accumulation of Zn in grains was the highest,and 58.1% of the Zn accumulation was distributed in grains at maturity.The total accumulation of Zn in wheat plant during its life span ranged from 384.9 to 475.9 g ha-1.The amount of Zn required for the formation of 100 kg grain yield ranged from 4.3 to 5.2 g.All the organs were ordered in such a sequence that leaf blades 〉 spikes 〉 leaf sheaths 〉 stems according to their net absorption and transportation of Zn as well as their contribution to Zn accumulation in grains.58.2-60.3% of the Zn accumulated in grains was redistributed from other organs,mostly from leaf blades.Concentration and accumulation of Zn in all the organs of wheat was high during early and middle growing periods,while accumulation of Zn in grains during late growing period mainly depended on the redistribution from other organs.According to these characteristics of Zn absorption and accumulation,Zn should be applied as seed dressing or basal fertilizer,so as to accelerate the early growth and Zn absorption of wheat.     

利用C基因组对高杆野生稻和宽叶野生稻基因组的比较分析(英文)

[Objective] Genomic in situ hybridization (GISH) was used to study the relationship between the two CCDD genomes of Oryza alta and Oryza latifolia. [Method] Total DNA of Oryza officinalis (C-genome) was used as a probe for genomic in situ hybridization on metaphase chromosomes from Oryza alta and Oryza latifolia, respectively. [Result] Under certain post-hybridization washing stringencies, C- and D-genome could be distinguished in CCDD genome type; there were huge differences in some CC chromosomes of Oryza alta, Oryza latifolia, and Oryza officinalis. The genome of Oryza latifolia was more original. [Conclusion] Comparative analysis of the Oryza species with identical genome type may facilitate to elucidate the possible approaches to plant genome evolution and species evolution.     

4种禾本科小麦族植物微观形貌特征比较研究

[目的]研究小麦族4种植物花粉粒和气孔的微现特征的异同,并探讨花粉粒和气孔大小与染色体组倍数的关系。[方法]通过扫描电镜对二倍体长稳偃麦草、中阍偃麦草、普通小麦、和八倍体小偃麦的花粉粒和叶表面的微观形貌特征进行了比较。[结果]4种植物在花粉粒形态、大小、表面突起,萌发孔和叶表面气孔大小方面存在一定的差异,其中二倍体长穗偃麦草与其他3种植物的花粉粒和气孔的微观特征差异明显。可见,小麦族二倍体物种与六倍体物种、八倍体物种在花粉粒和气孔的微观特征方面有明显差异,但六倍体和八倍体物种之间差异不明显。[结论]用花粉粒和气孔的一些微观特征作为鉴别二倍体和六倍体、八倍体等染色体组倍数相差较大的物种有一定的依据。     

禾本科三个物种花粉粒及叶片扫描电镜观察

[目的]比较八倍体小黑麦、二倍体黑麦以及普通小麦的微形态特征,探讨它们的染色体组倍性及亲缘关系。[方法]利用扫描电子显微镜对二倍体黑麦、普通小麦和八倍体小黑麦的花粉粒和叶片表面形态与微结构进行观察与比较。[结果]二倍体黑麦、普通小麦和八倍体小黑麦的花粉粒和叶片表面微观形态存在明显的差异,且八倍体小黑麦的一些微观形态特征介于二倍体黑麦和普通小麦之间。通过对比发现,三者的花粉粒大都为近圆形,在萌发孔和表面饰纹上有明显的差异,萌发孔从大到小依次为普通小麦、八倍体小黑麦、二倍体黑麦;在叶片下表皮特征、气孔大小和特征以及刺毛等方面,八倍体小黑麦都要明显不同于普通小麦和二倍体黑麦。[结论]花粉粒和叶片表面形态与微结构可作为区分种属差异的一项指标,同时对鉴定利用染色体工程创造的不同倍性新的多倍体物种以及研究物种的亲缘关系具有一定的参考价值。     

采用ISSR方法研究簇毛麦属与偃麦草属染色体组的遗传关系

[目的]确证簇毛麦属（Dasypyrum）与偃麦草属（Thinopyrum）物种不同基因组的系统发生关系。[方法]采用ISSR引物对12个小麦族物种扩增后进行了聚类分析。[结果]多年生簇毛麦（D.breviaristatum）、中间偃麦草（Th.intermedium）和二倍体长穗偃麦草（Lo-phopyrum elongatum）亲缘关系最近而聚在一起,而二倍体簇毛麦（D.villosum）与拟鹅观草（Pseduoroengeria spicata）聚在一起。[结论]多年生簇毛麦Vb基因组与偃麦草E基因组关系较近;二倍体簇毛麦和多年生簇毛麦未聚在一起,支持＂多年生簇毛麦不是二倍体簇毛麦加倍产生＂的观点。关键词簇毛麦属;偃麦草属;ISSR;聚类分析;遗传进化 更多还原     

禾本科3个物种花粉粒及叶片扫描电镜观察

以普通小麦（2n=6x=42）作母本,与二倍体黑麦（2n=2x=14）进行杂交,并进行染色体加倍,所获得的新物种就是八倍体小黑麦（2n=8x=56）。八倍体小黑麦的植物学形态介于双亲之间,兼有两者的性状。     

二倍体长穗偃麦草E组染色体研究进展

二倍体长穗偃麦草(Thinopyrum elongatum)E组染色体是组成偃麦草属(Thinopyrum)多倍体物种的基本染色体组,携带有对小麦遗传育种有益的基因,人们已从多方面解读了E组染色体与小麦及其他近缘种属的遗传进化关系。综述了二倍体长穗偃麦草E组染色体与比萨偃麦草和小麦的亲缘关系、生化标记、分子标记和高分子量谷蛋白研究的进展。     

棉种染色体倍性与叶片气孔性状的关系

观察了棉属(Gossypium)中不同染色体组的二倍体棉种、四倍体棉种及种间杂种共9个材料的叶片气孔,测定了气孔密度、气孔保卫细胞的大小、气孔最大开张程度及保卫细胞内叶绿体数目。结果表明,不同染色体组问、不同棉种间和不同染色体倍性间在这些性状上均存在明显的差异。并且。随着染色体倍性提高。四倍体棉种的气孔保卫细胞的大小和叶绿体数目增加,而气孔密度则比二倍体棉种的小。因此,认为通过对上述叶片气孔性状的测定分析,可以用于鉴定不同染色体倍性的棉花植株。     

Study on the Relationship Between the Ploidy Level of Microspore-Derived Plants and the Number of Chloroplast in Stomatal Guard Cells in Brassica oleracea

The relationship between the ploidy level of microspore-derived plants and chloroplast number in stomatal guard cells was studied in cabbage, broccoli, and Chinese kale. In the experiment, distribution statistics analysis and t-test were used to perform statistical analysis on chloroplast number of different ploidy level in those stomatal guard cells mentioned above, and morphology identifying and chromosome counting were used to test accuracy of counting chloroplast number in stomatal guard cells. The chloroplast average number in stomatal guard cells was very similar among the different leaf positions on the same plant and among the different locations in the same leaf, while the chloroplast number varied significantly among the different ploidy stoma in the same variety. All the distributions of the chloroplast number in different ploidy stoma were normal distribution fitted. A correlation has been established between ploidy and chloroplast number in the stomatal guard cells. In every single stoma of microspore-derived plants, the chloroplast number for a haploid should not be more than 10, diploids 11 to 15, and polyploids more than 15. The accuracy of this method for identification of different ploidy plants was 93.93%. Furthermore, the accuracy of this method was reliable and did not vary with the plants growth conditions. Therefore, the chromosome ploidy of plants derived from microspore culture in cabbage, broccoli, and Chinese kale can be identified by simply counting the chloroplast number in stomatal guard cells.     

铁皮石斛的生物学特性与开花授粉技术研究

[目的]研究铁皮石斛的生物学特性和开花授粉技术。[方法]采用实地考察、显微观察与统计分析的方法对铁皮石斛的表皮细胞、气孔器及其分布、花期进行了调查与分析,并对铁皮石斛花、果实和种子的主要特征、人工授粉方法及花粉粒保存方法进行了研究。[结果]铁皮石斛上表皮细胞排列整齐,每个细胞周围有5～7个细胞与其相邻;其气孔全部分布于下表皮;铁皮石斛花主要集中在6月下旬开放,从花芽萌发到花朵开放大约需要35 d;自然状态下的铁皮石斛很难完成授粉过程;铁皮石斛人工自花传粉成功率只有30%,人工异花授粉成功率为100%;室温即可实现花粉粒的保存。[结论]通过人工种内杂交授粉可以极大的提高铁皮石斛的结实率。     

赤苍藤显微特征鉴别

[目的]研究赤仓藤的显微结构特征。[方法]通过制作切片,观察赤仓藤茎、叶片及药材粉末的显微特征。[结果]赤仓藤茎横切面无明显特征;叶横切面下表皮有气孔,栅栏组织细胞1列,不过主脉,海绵组织与栅栏组织分化不明显;药材粉末中多见晶鞘纤维,细胞梭状,有多数细小淀粉粒。[结论]这些特征可作为赤仓藤的显微鉴别依据。