Quantitative evaluation of the three-dimensional fruit shape and size of Citrus species based on spherical harmonic descriptors

A measurement system, which consisted of a CCD laser displacement sensor and two pulse stages, was constructed to obtain three-dimensional (3-D) surface data of Citrus fruit. Fruits of 58 species of three specimens each were measured. By expanding the data measured in a series of spherical harmonic functions, a set of expansion coefficients to characterize the object shape was obtained. The data was normalized to make the coefficients be independent of the x- and y-coordinates of the object. To summarize the information about shape contained in the62 coefficients, a principal component analysis of the standardized spherical harmonic coefficients of each fruit was made. The contribution of each of the first seven principal components was found to exceed that of a single variable. The first three principal components had a cumulative contribution of 0.823.Analysis of variance showed that the variance due to between-species as tested against the variance due to within-species was significant for the 1^st,2^nd, 3^rd, 4^th, 7^thcomponent score and the volume. A scatter diagram of the 1^st and 2^nd principal components failed to group the species studied. This revised version was published online in July 2006 with corrections to the Cover Date.     

抗战胜利70周年活动期间河北南部环境气象条件分析及应急减排效果研究

为研究抗战胜利70周年活动期间气象条件对空气污染的影响和应急减排效果,以河北南部邯郸为例,利用2015年8月1日—9月3日邯郸环境监测站数据、邯郸气象站气象资料进行分析。结果表明,应急减排期间（8月23日—9月3日）邯郸市大气污染物浓度明显下降,8月23日—9月3日全市PM_2.5平均浓度比减排前（8月1—22日）下降46.3%,9月1—3日全市连续3天空气质量达优。从逆温强度、混合层高度、通风系数、风速、小风日数、降水等气象条件及后向轨迹分析表明,减排期间大部分时段受静稳天气影响,不利于空气污染物垂直扩散;气团后向轨迹分析表明：以本地气团为主;应急减排使相同气象条件下污染物浓度明显下降,有力的减排措施是空气质量改善的根本原因。     

Construction of a genetic map of melon with molecular markers and horticultural traits, and localization of genes associated with ZYMV resistance

Abstract: A partial linkage map of melon was constructed from a cross between PI414723 and Dulce. Twenty-two SSR, 46RAPD, 2 ISSR markers and four horticultural markers [female flower form (a), Fusarium resistance, striped epicarp (st), and fruit flesh pH (pH)] were analyzed in an F₂/F₃ population to produce a map spanning 14 linkage groups. We report for the first time map positions for the st, a, and pH genes. One SSR marker was tightly linked to pH. Mapping the a gene for the female flower form to molecular linkage group 4 enabled the merging of the map of horticultural traits with the of molecular markers in this region. Using the 22 SSR markers of this map, two of the three postulated ZYMV resistance genes were located using a BC₁ population (PI414723 recurrent parent). One SSR marker was tightly linked to a ZYMV resistance gene, designated Zym-1. This revised version was published online in August 2006 with corrections to the Cover Date.     

Rice root morphology under contrasting moisture regimes and contribution of molecular marker heterozygosity

Evaluation for root morphology and related characters at three different stages and different moisture regimes was made using 9backcross populations obtained by crossing selected doubled haploid lines derived fromIR64 × Azucena with IR64. Marked genotypic differences were observed for all the characters across three samplings. In samplings at 80 days after sowing, significant reductions in mean root and shoot dry weights were noticed from well-watered to severely-stressed conditions, but higher root to shoot dry weight ratios were observed under severe stress condition. In the samplings at maturity, significant increases in mean values of all characters except shoot dry weight and root number, were observed from both well watered to stress conditions. However, individual backcross populations varied with respect to root and shoot dry weights across the moisture regimes. Estimates of heritability were reduced from the 1^st to 3^rd samplings as well as from WW to SS conditions. In the third sampling, root volume, root thickness and maximum root length were found to be interrelated. The experimental materials were classified into two distinct groups by dendrogram based on 175 markers. This classification was fairly similar to phenotypic classification based on root morphology with IR64 and Azucena falling into the respective main groups. Correlations of marker heterozygosity with hybrid performance and heterosis differed markedly between the 2^nd and 3^rdsamplings as well as between well watered and severe stress conditions. This revised version was published online in August 2006 with corrections to the Cover Date.     

Field evaluation of insect-resistant transgenic Populus nigra trees

The performance of insect-resistant transgenic poplar trees (Populusnigra) expressing a Cry1Ac gene from Bacillus thuringiensis subsp. Kurstaki HD-1 against poplar defoliators was evaluated in the field at the Manas Forest Station in Xinjiang Uygur Autonomous Region during1994–1997. The results showed that the average percentage of highly damaged leaves on the transgenic trees was 10% while that on the control trees in nearby plantations reached 80–90%. The average number of pupae per m² of soil at 20cm depth in transgenic poplar plantation was 18 which was only 20% of that found in the non-transgenic control field. The number of pupae and the leaf-damage on transgenic trees described above are all far below the threshold set for chemical protection measures. The non-transformed poplar trees grown in the same plantation with the transgenic trees were also protected indicating that cross protection occurred between these two kinds of trees. Insect-resistant transgenic poplar trees have a potential application value in afforestation. This revised version was published online in August 2006 with corrections to the Cover Date.     

Micropropagation of <Emphasis Type="Italic">Kaempferia angustifolia</Emphasis> Roscoe - An Aromatic,Essential Oil Yielding,Underutilized Medicinal Plant of Zingiberaceae Family

Kaempferia angustifolia is an aromatic, essential oil-yielding plant of the Zingiberaceae family with an ethno-medicinal repute. We standardized an effective system for micropropagation of K. angustifolia, and this is probably the very first report of in vitro culture of this species. Axillary buds were cultured on a Murashige and Skoog (MS) medium supplemented with various concentrations and combinations of plant growth regulators (PGRs) and spermidine. Highest multiplication occurred when the MS medium was supplemented with a combination of 2.0 mg L^?1 6-benzylaminopurine (BAP), 2.0 mg L^?1 kinetin (KIN) and 1.0 mg L^?1 α-naphthalene acetic acid (NAA). Addition of spermidine (2.0 mM) along with optimum PGRs had further improved the multiplication rate with a maximum of 6.6 ± 0.36 shoots per explant within 60 days of implantation. The number of multiplied shoots per explant increased with each subsequent regeneration cycle; and the shoots per explant increased from 6.6 ± 0.36 on the 1^st regeneration cycle to 10.3 ± 0.42 on the 2^nd regeneration cycle and further increased to 13.7 ± 0.37 on the 3^rd regeneration cycle on the same medium composition. The best result for in vitro root induction of multiplied shoot was achieved on a half-strength MS medium fortified with 2.0 mg L^?1 IBA, with a maximum of 18.5 ± 0.28 roots per shoot. Regenerated plantlets were acclimatized with 88.9 % survival rate. After 9 months of field-transfer, all these plants were harvested and rhizomes were collected. However, the present protocol can definitely be applied for large-scale propagation and commercial cultivation of K. angustifolia.     

Construction and characterization of a BAC library for sunflower (Helianthus annuus L.)

A bacterial artificial chromosome (BAC) library was constructed using the sunflower (Helianthus annuus L.) restorer line RHA325, which carries the restorer gene Rf1 and the Pl2-gene conferring resistance to downy mildew. High molecular weight DNA was prepared from nuclei using leaf material from two-week old seedlings. The library was constructed using the HindIII site of pBeloBAC11. The current BAC library comprises 104,736 clones. The insert size of the clones varied between 20 and 270 kb, with an average insert size of 60 kb. The whole 1.9× sunflower BAC library was spotted in duplicate on four high-density filters, each carrying 55,296 clones. The content of organellar DNA, which was estimated by colony hybridisation against the mitochondrial probe coxI and the chloroplast probe rbcL, proved to be less than 0.03 and 0.1%, respectively. BAC pools, allowing PCR-based screening, were made and used to identify positive BAC clones for the markers OP-K13_454, closely linked to the restorer gene Rf1. The PCR-based screening was verified by the results obtained for this marker by colony hybridisation.     

Genetic parameters for nut and kernel traits in macadamia

Data from a trial of 40 cultivars clonallyreplicated over five locations were used to estimatebroad-sense heritability and genetic and phenotypiccorrelations for important nut and kernel traits inmacadamia (Macadamia integrifolia and M.tetraphylla). Location averages for each cultivarwere available from 4 to 10 years after planting fornut mass, kernel mass, kernel recovery, percentage1^st grade kernels and percentage whole kernels,with individual tree measurements only available forone year. Heritability estimated from locationaverages was inflated for all traits due tounderestimation of the phenotypic variance. Un-confounded estimates of individual broad-senseheritability, obtained by combining information fromboth data sources, was high (H = 0.63) fornut and kernel mass, and kernel recovery, moderatefor percentage whole kernels (H 0.30) and low for percentage 1^stgrade kernel (H 0.20). There waslittle interaction between cultivar and location orage; however, for percentage 1^st grade and wholekernels, there were large 3-way and 4-wayinteractions. The only strong genetic correlation wasbetween nut and kernel mass (r _g = 0.80). Theimplications of the results for cultivar selection andbreeding programs are discussed.     

种子休眠与萌发综述

种子休眠是高等植物中显花植物(即裸子植物和被子植物)经过长期进化而获得的一种对环境条件及季节性变化的生物学适应。休眠的种子可以在不适宜幼苗生长的情况下阻止种子的萌发,减少子代在恶劣环境萌发的的风险,一定程度上保障了种群的延续。本综述重点介绍种子休眠的类型、外界环境因素与母体环境因素以及植物激素对种子休眠与萌发的影响,并介绍了休眠的进化,各种不同类型的休眠在系统发生树上的分布,以期在阐明种子休眠机制的基础上提出一些解决生产过程中种子休眠问题的方法与路径,并为破坏严重的野生植物资源的保护,引种栽培提供理论依据。     

Cytological and microsatellite mapping of mutant genes for spherical grain and compact spikes in durum wheat

Two mutants for sphaerococcoid seed (MA 16219) and compact spike (MA 17648) were isolated from M₃ progeny of durum wheat cultivar, Altaiskaya Niva, mutagenized with chemical mutagens. The chromosomal locations of the genes involved were determined by the use of a complete set of D-genome disomic substitutions in durum cultivar, Langdon. The gene for sphaerococcoid grain, s ¹⁶²¹⁹ , was allelic to S2, located in the centromeric region of chromosome 3B in hexaploid wheat. The gene for compact spike, C ¹⁷⁶⁴⁸ , was located on chromosome 5AL distal to the Q locus. Using microsatellite markers, C ¹⁷⁶⁴⁸ and awn inhibitor B1 were located in the F₂ of LD222 × MA17648. The gene order was Xbarc319—C ¹⁷⁶⁴⁸ —Xgwm179—Xgwm126—Xgwm291—B1.     

Association analysis of five candidate genes with plant height and dry matter yield in perennial ryegrass

Five candidate genes LpIAA1, LpRUB1, LpBRI1, LpSHOOT1 and LpTB1 with putative function in plant architecture were allele sequenced in a panel of 96 diploid perennial ryegrass genotypes of diverse origin. The total length of the non‐redundant genomic DNA alignment was 5425 bp and revealed 270 polymorphic sites in total. A negative significant Tajima's D value was detected in LpTB1 gene, suggesting selection pressure for low‐frequency alleles in this gene. All 96 genotypes were evaluated for plant height and dry matter yield over two years. Marker–trait associations were calculated between polymorphic sites and both phenotypic traits. Three indels and three single nucleotide substitutions in LpTB1 gene were significantly (P < 0.05, q < 0.05) associated with plant height, while one indel was associated with dry matter yield. The results suggest putative role of LpTB1 gene in plant height determination in perennial ryegrass and provide means for target allele selection.     

不同水稻种质中渗透胁迫抗性基因DREB2A的遗传多样性分析

本研究旨在分析转录因子DREB2A基因在不同水稻种质中的遗传多样性,以期为水稻耐渗透胁迫遗传改良提供分子工具。利用单倍型分析、系统进化树、遗传距离和密码子偏好性分析,对85份不同类型水稻种质中DREB2A基因的功能性核苷酸序列变异及遗传多样性进行了研究。共鉴定出55个核苷酸变异位点,其中12个位于编码区,43个位于非编码区;鉴定出12个DREB2A等位基因型,其中来自非洲栽培稻(Oryza glaberrima)的3个等位基因型表现大片段变异;根据DREB2A基因的序列变异鉴定出39个单倍型,其中33个为新单倍型;将所有单倍型分为三组（Group I、II和III）,其中非洲栽培稻(Oryza glaberrima)中的10个单倍型单独分为一组(Group III);系统进化树、遗传距离和密码子偏好性分析均表明Group III与其他两组具有较大差异。对85份不同类型水稻种质中DREB2A基因的序列分析表明,非洲栽培稻(Oryza glaberrima)中的DREB2A等位基因在序列变异、系统进化关系和密码子偏好性方面均明显不同于其他种质材料中的等位基因。     

Phylogenetic analysis of plastid trnL-trnF sequences from Arisaema species (Araceae) in Korea

The phylogeny of 10 taxa belonging to three sections of Arisaema (Pistillata, Tortuosa, and Arisaema) distributed in Korea and an outgroup taxon (Pinellia ternate) was analyzed by comparing the trnL(UAA)-trnF(GAA) intergenic spacer sequences of the chloroplast DNA (cpDNA). The trnL-trnF regions ranged from 336 to 396 base pairs (bp) in length. Sequence alignment required 18 base substitutions and 4 independent indels in the region. The longest length mutation was a 35-bp deletion in A. thunbergii, A. heterophyllum, A. urashima, and A. candidissimum. Two different restriction fragment patterns were seen with MspI digestions. Section Tortuosa (A. thunbergii and A. heterophyllum) plus A. urashima and A. candidissium were distinguished from the others. In addition, 16-bp deletions were found in A. thunbergii, A. heterophyllum, and A. candidissimum. Four species possessed a 24-bp insertion mutation with a duplication motif, TTTTGTTAGGTTATCCTTACACTT:A. amurense f. serratum, A. robustum f. purpureum, A. peninsulae, and A. sikokianum. A maximum parsimony analysis of 11 accessions produced 12 equally most-parsimonious (MP) trees. The MP trees also contained three independent groups. Group I contained one taxon:A. ringens f. praecox. Group II contained the section Tortuosa accessions including A. urashima and A. candidissimum. Group III contained the section Arisaema and A. sikokianum. These results show that analyses of the cpDNA trnL-trnF intergenic spacer are a useful approach for inferring phylogenetic relationships and identification within the genus Arisaema, distributed in Korea. This revised version was published online in August 2006 with corrections to the Cover Date.     

In vitro screening of strawberry plants for cold resistance

Formation of embryo autonomy of strawberry, plant regeneration fro membryo components, plant freezing conditions in vitro and the possibility to differentiate objectively genotypes by freezing them in vitro and in vivo were studied to create strawberry screening technology in vitro for cold resistance. It was established that autonomy of strawberry embryos manifests itself not earlier than on 14–16^th day after pollination and full autonomy is reached on 20–22^nd day. Plants regenerated from 26 days old embryos grew most intensively. At the highest rate strawberry plants regenerated from an isolated embryo axis on MS medium without phytohormones, and from rescued cotyledons x on the medium with 1.0 BA and 0.5 NAA. The temperature interval, at which genotypes differentiated according to cold resistance in vitro, was -8 to 12 ^°C. Differentiation of strawberry genotypes according to this character conformed to their differentiation in vivo, provided hardening proceeded not less than 21 days. The correlation between cold resistance in vitro and in vivo reached 0.93. Domination of cold resistance manifested itself in strawberry seedlings from various crossing combinations. This revised version was published online in August 2006 with corrections to the Cover Date.     

叶甲科部分种类 Cyt b基因序列及系统发育关系初探

测定分析了叶甲科(Chrysomelidae)15种昆虫mtDNA_Cyt b基因部分序列,结果显示,在获得的390 bp序列中,198个核苷酸位点为多态性位点(约占50.8%),序列间碱基差异平均值为18.9%,A T含量为72.7%,碱基转换呈现明显的TC偏向性,颠换主要以TA为主,转换/颠换(R)值为0.8。依据分子数据建立了该15种昆虫的系统发育关系,结果表明:跳甲亚科(Alticinae)和叶甲亚科(Chrysomelinae)的亲缘关系较近,萤叶甲亚科(Galerucinae)与前两者的关系较远。萤叶甲亚科中瓢萤叶甲为最早分化的类群,长跗萤叶甲属(Monolepta)、凹翅萤叶甲属(Paleosepharia)、长刺萤叶甲属(Atrachya)能形成姊妹群。克萤叶甲属(Cneorane)和守瓜属(Aulacophora)的亲缘关系较近。基于蛋白质序列构建的系统树的置信值高于核苷酸序列建立的系统发育树。     

Breeding two base populations of perennial ryegrass

Summary A program designed to develop two base populations of perennial ryegrass was initiated in 1985 in Galicia. Multitrait mass selection by a base index was practised in two genetic resources groups of wild Galician populations. Plants selected were intercrossed and the two resulting base populations (F and G) were evaluated in two locations at the spaced plant level and in plot trials with the aim of estimating the genetic parameters and the possibilities for future breeding. The two populations did not show significant differences from commercial cultivars. Production characters had low heritabilities (0.01–0.32) in both locations. Seasonal yields had medium to high family heritabilities (0.36–0.73). For the economic traits chosen, the expected genetic advances were important in both populations for summer and autumn growth in Mabegondo and spring and summer-autumn dry matter yield (1^st and 3^rd year) in Puebla de Brollón. Expected genetic advance for early spring growth was 0.62 in population F. In the autumn of 1991 equal numbers of plants, selected at each location by combined family and mass selection from each of these populations, were planted in two polycrosses with the aim of improving the genetic basis and adaptation of these populations.     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.     

Polymorphisms of the <Emphasis Type="Italic">FT</Emphasis> gene as a tool to identify underground rhizome types of bamboos

The Flowering Locus T (FT)-like genes of angiosperms are highly conserved. The FT-encoded proteins include a phosphatidylethanolamine-binding domain that is involved in the control of the shoot apical meristem identity and flowering time. In the present study, FT genes were investigated in 20 bamboo species that are grouped into sympodial, mixed and scattered bamboos based on their morphology. All examined orthologous FT genes consisted of four exons and three introns. Their encoded protein sequences contained the critical amino acid residues Tyr85, Glu109, Leu128, Tyr134, Trp138, Arg139, Gln140 and Asn152, of which each possesses a biological function. The DNA sequences were rich in single nucleotide polymorphism (SNP) sites. The SNP frequency was 1 SNP/16.8 bp, and the nucleotide diversity (π) equaled 0.265. Some SNPs altered restriction enzyme sites or resulted in changes in amino acid contents. The correlation analysis showed that several SNPs were informative in relation to the underground rhizome types of bamboos. Therefore, FT polymorphisms could be used as a tool to identify the underground rhizome types of bamboos. The phylogenetic tree constructed based on the FT gene sequences showed that the obtained clustering was consistent with the underground rhizome types. The SNP markers developed in the present study will provide information on the genetic diversity of bamboos and they can aid taxonomic study as well.     

Haplotype structure in grain weight gene GW2 and its association with grain characteristics in rice

GW2, a grain weight quantitative trait locus (QTL) in rice encodes a ring type E-3 ubiquitin ligase. A single nucleotide deletion at the 346th nucleotide position in the ligase domain of GW2 was earlier reported to result in higher grain weight in rice. The present study aimed at validating the known functional polymorphism and identifying additional natural genetic variation if any, in the region that included the functional domain of GW2 in a set of indica and aromatic genotypes for which ninety three rice genotypes were phenotyped for grain length, grain width and 100 grain weight. A wide range of variation was observed for these traits. PCR amplification and sequencing of GW2 target region revealed absence of insertion/deletion (InDel) at the 346th position which suggested that the genetic variation in grain weight in Basmati and non-Basmati indica genotypes was not explained by this InDel. However, four new single nucleotide polymorphisms (SNPs) were discovered at nucleotide positions 406, 461, 466 and 501 in the fifth exon and one InDel each in second and fourth introns. Only two of these SNPs, at positions 461 and 501 led to amino acid substitutions. A total of 10 haplotypes were constructed based on these four SNPs which could be regrouped into four categories based on their amino acid substitutions. Association genetic analysis of these haplotypes with different grain traits revealed a moderate association with grain width (R² = 0.18 at P < 0.05). Thirteen haplotypes constructed using both intronic and exonic polymorphisms did not have any association with grain traits.     

Genetic characterization of group A acetylsaponin‐deficient mutants from wild soybean (Glycine soja Sieb. and Zucc.)

Group A acetylsaponins are the main causative components for bitter and astringent tastes of soybean (Glycine max). In this study, we examined the genetic nature of the absence of group A acetylsaponins in 12 Korean wild soybean (Glycine soja) accessions. In all 12 accessions, the coding region (1431‐bp) of Sg‐1 locus was identical with Sg‐1^a, which adds the xylose sugar moiety at the terminal position of the C‐22 sugar chain of SS‐A, except one nucleotide (G→A change) at +948th position. This point mutation results in change of one amino acid from tryptophan (TGG) to stop codon (TGA). We observed that the mutated Sg‐1 was controlled by a single recessive gene (sg‐1^0‐a1). This gene was mapped between BARCSOYSSR_07_1561 and BARCSOYSSR_07_1598 on soybean chromosome 7. Our study demonstrated that the mutated Sg‐1 gene in Korean wild soybeans is genetically different from those identified in Japanese soybean cultivar ‘Kinusayaka’ and wild soybean JP‐36121. We believe that the new Sg‐1 mutants can also be utilized to produce a new soybean variety without bitter and astringent properties.