Hybridizing <Emphasis Type="Italic">Brassica rapa</Emphasis> with wild crucifers <Emphasis Type="Italic">Diplotaxis erucoides</Emphasis> and <Emphasis Type="Italic">Brassica maurorum</Emphasis>

Two wide hybrids, Diplotaxis erucoides (2n = 14) × Brassica rapa (2n = 20) and B. maurorum (2n = 20) × B. rapa, were developed using the sequential ovary–ovule culture. Reciprocal crosses failed, possibly as a consequence of strong unilateral incompatibility. The F ₁ hybrids in each combination were completely male sterile and morphologically intermediate to the respective parents. DNA marker polymorphism and chromosome counts confirmed their hybrid nature. High frequency of bivalents in the F ₁ and the presence of trivalents/quadrivalents in the derived amphiploids suggested genomic duplications and homoeology of the parental genomes. Up to three homoeologous pairs between the D. erucoides (D^eD^e) and B. rapa (AA) genomes, and one between B. maurorum (B^mB^m) and B. rapa genomes were observed. Successful synthesis of the F ₁ hybrids and amphiploids of B. rapa with D. erucoides and B. maurorum, and allosyndetic chromosome pairing are expected to permit introgressions of desirable loci into the cultivated Brassica germplasm, especially for resistance to Alternaria brassicae and Albugo candida.     

亲水性液相色谱串联质谱法测定红甜菜中甜菜碱含量

为了建立红甜菜中甜菜碱的定量分析方法,采用改进的QuEChERS方法结合液相色谱串联质谱技术,样品经快速溶剂萃取仪以甲醇为溶剂提取,经固相萃取柱净化,采用正向亲水性液相色谱柱(Hilic),梯度洗脱,通过质谱的多反应监测(multiple reactions monitoring,MRM)正离子模式扫描进行测定,外标法定量。结果表明：甜菜碱在本方法的线性范围为0.05~5 ug/mL,添加水平为4~16 mg/g时,回收率为87.7%~95.7%,方法RSD值为3.69%~8.4%,检出限为0.01 mg/L,定量限为0.04 mg/L,与传统的分析方法相比,具有检出限低、灵敏度高的优点,完全可以适用于甜菜中甜菜碱的分析。     

科普须防“失真”，“失声”，“失效”

为了提高对科普工作的重视程度,依靠动员科学家推动科普事业,加强科普资源建设,创新科普活动,针对科普工作和活动经常出现“权威性不够”,“针对性不足”,“实效性不强”等问题。根据长期从事农业科普工作的实践,对科普“失真”,“失声”,“失效”现象产生的原因进行了深入思考,提出了解决这些问题的主要对策建议。     

‘Pasifika’ and ‘I‐Kiribati’ identity in Aotearoa New Zealand: ‘Dancing’ and ‘edge‐walking’ through multiple identities

This article explores the relationship between I‐Kiribati communities and the broader ‘imagined’ Pasifika community in Aotearoa New Zealand. It looks at the way a group of I‐Kiribati tertiary students experience identity within this context. Through the use of semi‐structured interviews and a discourse analysis, the study draws three main conclusions. First, that I‐Kiribati navigate multiple identities and are constantly negotiating these within different spaces. Although this contributes to uncertainties around identity, I‐Kiribati students also strategically enact identity to suit various contexts. Second, that Pasifika as a term tends to infer ‘Polynesian’ which in turn may marginalise I‐Kiribati identities within certain spaces, particularly in education settings that intend to support all Pacific identities. Yet, given such a narrow understanding of Pasifika, these efforts may counter that intention for those on the margins of, or outside the common usage of, the term Pasifika. Last, community plays a significant role in the formation of identities within minority groups, which is important for countering aspects of marginalisation experienced within broader pan‐ethnic labels such as Pasifika. Consequently, we argue that Pasifika as a label needs to better reflect inter‐Pacific diversity as well as the identity negotiations that Aotearoa New Zealand‐born Pacific peoples navigate.     

不同施肥处理对特菜-根芹菜产量和硝酸盐积累的影响

摘 要：根芹菜是我国引进的一种稀特蔬菜品种。田间小区试验研究了有机肥及与无机肥配施处理对根芹菜产量、硝酸盐含量及氮肥利用率的影响。结果表明：有机无机配合适宜氮磷钾比例施肥处理下N1（261kgN/hm2）根芹菜产量最高,显著高于其他处理,地下可食部分硝酸盐含量与对照相比没有显著差异,也有较高的氮肥利用率;N2、N3较高氮肥处理下产量显著低于N1处理,特别是N3处理下产量与对照相比没有显著差异,但硝酸盐含量随施氮量的增加而增加。以上结果说明,较高肥力菜田土壤上适宜氮磷钾比例的有机无机肥配施有利于提高根芹菜产量和保持良好品质。     

Haplotype analysis of <Emphasis Type="Italic">Viviparous</Emphasis>-<Emphasis Type="Italic">1</Emphasis> gene in CIMMYT elite bread wheat germplasm

Pre-harvest sprouting (PHS) greatly reduces the quality and economic value of wheat grain. In this study, a total of 168 International Maize and Wheat Improvement Center (CIMMYT) wheat germplasm lines were examined to characterize the haplotypes of Vp-1A, Vp-1B and Vp-1D, which are located on the long arms of chromosomes 3A, 3B and 3D, respectively. Among them, five new alleles of Vp-1Aa (the wild allele) were identified on chromosome 3A, and designated as Vp-1Ab, Vp-1Ac, Vp-1Ad, Vp-1Ae and Vp-1Af, respectively. The main difference between Vp-1Aa and the newly identified alleles was in the numbers of CTT repeats located in the third intron, but Vp-1Af also had 6 and 2 bp deletions at positions 2860–2865 bp and 2880–2881 bp, and possessed five SNPs within the same intron region. In the Vp-1B locus, several alleles (Vp-1Ba, Vp-1Bb, Vp-1Bc, Vp-1Bd, Vp-1Be and Vp-1Bf) have already been identified. In the present material only two, the already known allele Vp-1Bc, and a new one, designated as Vp-1Bg, were detected. Compared with Vp-Ba, Vp-1Bg had additional insertion of TCC at position 2372 bp and a 9 bp change from CTGCATC AC to GCATCAGTG at 2417–2425 bp. However, no polymorphism was detected in Vp-1D. The frequencies of Vp-1Aa Vp-1Ab, Vp-1Ac, Vp-1Ad, Vp-1Ae, and Vp-1Af were 65, 10, 11, 4, 5 and 5%, respectively. For Vp-1B, 155 out of the 168 lines were Vp-1Bc; the remaining 13 were Vp-1Bg. Analyses of the germination index (GI) and abscisic acid (ABA) sensitivity showed that genotypes with Vp-1Ab or Vp-1Af showed higher PHS resistance than the ones with other alleles, suggesting that they might be valuable for CIMMYT breeding program or germplasm introduction. The results presented here will underpin the introduction of germplasm from CIMMYT and the improvement of PHS resistance, both in CIMMYT and elsewhere.     

AFLP–SSR maps of maize × teosinte and maize × maize: comparison of map length and segregation distortion

Two genetic linkage maps of Zea mays were constructed: one population comprised 94 F₂ individuals of a dent ‘B64’ × teosinte (Z. mays ssp. huehuetenangensis) cross while the second consisted of 94 F₂ individuals of a ‘B64’ × Caribbean flint ‘Na4’ cross. The level of polymorphism was higher in the ‘B64’ × teosinte combination than the ‘B64’ × ‘Na4’ combination. In the ‘B64’ × teosinte cross, a total of 338 amplified fragment length polymorphism (AFLP) and 75 simple sequence repeat (SSR) markers were mapped to 10 chromosomes, which covered 1402.4 cM. In the ‘B64’ × ‘Na4’ cross, a total of 340 AFLP and 97 SSR markers were mapped to 10 chromosomes, covering 1662.8 cM. Segregation distortion regions were found on chromosomes 4, 5 and 8 in the ‘B64’ × teosinte cross and on chromosome 9 in the ‘B64’ × ‘Na4’ cross. Comparison of the two maps revealed that the maize × teosinte map was 11.5% shorter than the maize × maize map. The maps generated in this study may be useful to identify genes controlling flooding tolerance.     

A 192bp allele at the <Emphasis Type="Italic">Xgwm261</Emphasis> locus is not always associated with the <Emphasis Type="Italic">Rht8</Emphasis> dwarfing gene in wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

The height-reducing gene Rht8 was introduced into Italian wheats by breeder Nazareno Strampelli from the Japanese landrace Akakomugi, and has been widely used in wheats adapted to southern and eastern European conditions. Following identification of a close linkage to Rht8, microsatellite marker Gwm261 has been used extensively to screen large numbers of diverse international germplasm. A 192bp allele at this locus has been taken as “diagnostic” for Rht8 and used to infer the international distribution of Rht8. In this paper, we report several instances of cultivars and mapping populations that vary for the presence of the 192bp allele at the Xgwm261 locus (Xgwm261 ₁₉₂ ), but with no associated reduction in height, suggesting a lack of association with Rht8. For instance, in the population derived from a cross between Sunco (Rht-B1b, Xgwm261 ₁₆₅ ) and Tasman (Rht-D1b, Xgwm261 ₁₉₂ ), there were significant height differences associated with the segregation of Rht-B1b and Rht-D1b, but no height differences between Xgwm261 genotypes. Similar results were obtained in a population derived from the cross between Molineux (Rht-B1b, Xgwm261 ₁₉₂ ) and Trident (Rht-D1b Xgwm261 ₂₀₈ ). In contrast, the cross between Trident and Chuanmai 18 (Xgwm261 ₁₉₂ ) gave significant height effects at both the Rht-D1 and Xgwm261 loci, with no epistatic interaction between loci. Chuanmai 18 is closely related to the Strampelli wheat Mara (ancestrally derived from Akakomugi) and is therefore likely to carry Rht8. The old Japanese cultivar Norin 10, used by Norman Borlaug to introduce Rht-B1b and Rht-D1b into Mexican wheats, also has a 192bp allele at the Xgwm261 locus, and the sequence of the amplified product is identical to that of Akakomugi. We suggest that the widespread use of Norin 10-derived germplasm during and after the Green Revolution introduced a second haplotype into international germplasm, in which Xgwm261 ₁₉₂ has no association with Rht8. Therefore, the presence of Xgwm261 ₁₉₂ is only indicative of Rht8 in wheat cultivars that have inherited this allele from Akakomugi or a Strampelli wheat ancestor.     

Molecular mapping of soybean seed tocopherols in the cross ‘OAC Bayfield’ × ‘OAC Shire’

Soybean (Glycine max [L.] Merr.) is cultivated primarily for its protein and oil in the seed. In addition, soybean seeds contain nutraceutical compounds such as tocopherols (vitamin E), which are powerful antioxidants with health benefits. The objective of this study was to identify molecular markers linked to quantitative trait loci (QTL) that affect accumulation of soybean seed tocopherols. A recombinant inbred line (RIL) population derived from the cross ‘OAC Bayfield’ × ‘OAC Shire’ was grown in three locations over 2 years. A total of 151 SSR markers were polymorphic of which a one‐way analysis of variance identified 42 markers whereas composite interval mapping identified 26 markers linked to tocopherol QTL across 17 chromosomes. Individual QTL explained from 7% to 42% of the total phenotypic variation. Significant two‐locus epistatic interactions were identified for a total of 122 combinations in 2009 and 152 in 2010. The multiple‐locus models explained 18.4–72.2% of the total phenotypic variation. The reported QTL may be used in marker‐assisted selection (MAS) to develop high tocopherol soybean cultivars.     

Einfluß der Bestandesdichte auf Ertrags- und Qualitätskriterien sowie über mögliche Ursachen der Konkurrenz in Zuckerrübenbeständen

Influence of Plant Density on Yield and Quality and Possible Causes of Competition in Sugar Beet Crops
In trials conducted over 9 years at 1 location plant densities ranged from 35,000 to 110,000 plants/ha. Root yield, sugar yield and white sugar yield reached maximum values at 92,700, 94,700 and 96,000 plants/ha, respectively. The decrease in yield per 1,000 plants/ha was greater as the plant density fell. The quality criteria (sugar concentration, white sugar concentration and sugar gain) were at their maxima at 107,000, 104,600 and 100,000 plants/ha, respectively, and they decreased at an almost constant rate as plant density declined. The concentrations of potassium, sodium and amino-N, the main factors which determine quality in Germany, as well as the sugar loss were all minimized at about 110,000 plants/ha and they increased at a progressively-greater rate per 1,000 plants/ha as plant density declined. The maximum differences between large and small plant densities were: root yield 13.6%, sugar yield 16.7%, white sugar yield 18.6%, sugar concentration 3.7%, white sugar concentration 5.3%, sugar gain 1.7%, sugar loss 9.3%, potassium concentration 8.4%, sodium concentration 30.5% and amino-N concentration 25.4%. As well as a comparison of the yield and quality criteria, the paper considers competition within the foliage, particularly when different amounts of nitrogen are available, as the main cause for yield differences between sugar beet crops.     

柱花草种质抗旱性综合评价

对我国目前主要推广种和部分引进的柱花草种质进行抗旱性综合评价。采用完全随机区组设计,4梯度人工控水干旱,测试其各项形态指标和生理指标,选出与水分胁迫达极显著相关的8项指标,用隶属函数值法,对44份柱花草种质的抗旱性综合评价。与抗旱性成正相关的指标为：相对生物量、相对株高、叶片抗旱级别、相对qP、相对脯氨酸含量、相对Fv/Fm、相对Fv’/Fm’;负相关的有：相对电导率。抗旱性综合评价显示,抗旱性最强的依次为：热研5号、USTPRC90139、爱德华①、爱德华②和CIAT11369;最弱的依次为：CPI18750A、TPRC90037②、TPRC90037③和TPRC90028。聚类分析将44份柱花草种质抗旱性可分为3类：高抗旱性10份、中抗旱性15份、低抗旱性19份。本研究为筛选柱花草优良种质和育种材料提供了理论和实践的科学数据。     

Strahlungsnutzung durch Bestände ölreicher Körnerfruchtarten — Winterraps, Öllein und Sonnenblume im Vergleich

Radiation use by oil seed crops — a comparison of winter rape, linseed and sunflower For the production of grain crops rich in oil, winter rape, linseed and sunflower are similarly suitable at many arable locations. We wanted to compare the extent to which radiation (PAR) is intercepted and utilized by the individual species for dry matter and yield production. For this purpose, a 2‐year field experiment comprising the factors genotype, N fertilization and soil tillage was conducted. For five phases of crop development, growth rates (CGR, RGR and NAR) and PAR utilization were calculated. At full ripeness, total dry matter, grain, oil and energy yields, the crop‐ and year‐specific PAR supply, its interception and utilization for dry matter production and the resulting energy binding were determined. Due to the different individual vegetation periods, the PAR supply of the crops differed. The crop assimilation areas also differed, with values for winter rape and sunflower higher than those for linseed. The yield productivity of winter rape and sunflower was also higher than that of linseed. N fertilization increased yield to different extents for the different crops. On average, winter rape and sunflower produced the same amounts of dry matter and energy yield. Due to a higher harvest index, sunflower had the highest grain yield, and because the oil concentration in grain was comparatively high sunflower produced the highest oil yield, too. Under cool and wet climate conditions, however, the productivity of sunflower is offset by a relatively high yield risk because of uncertain ripening. The highest PAR utilization by linseed did not compensate for its very short vegetation period in combination with the lowest PAR interception.     

Quantitative resistance and its components in 16 barley cultivars to yellow rust, <Emphasis Type="Italic">Puccinia striiformis</Emphasis> f. sp. <Emphasis Type="Italic">hordei</Emphasis>

Sixteen barley cultivars with a susceptible infection type (IT = 7–8) in the seedling stage to an isolate of race 24 of Puccinia striiformis f. sp. hordei were planted at two locations in México. Disease severity (DS) parameters were assessed for the flag leaf and for the upper three leaves. The cultivars represented at least five levels of quantitative resistance ranging from very susceptible to quite resistant. “Granado”, “Gloria/Copal” and “Calicuchima-92” represented the most resistant group and had an IT of 7 or 8. The cultivar × environment interaction variance, although significant, was very small compared with the cultivar variance. The disease severity parameters were highly correlated. The monocyclic parameter DS_m, measured when the most susceptible cultivar had reached its maximum DS, was very highly correlated with the area under the disease progress curve (AUDPC), r being 0.98. Components of quantitative resistance were evaluated in two plant stages. In the seedling stage small cultivar effects for the latency period were observed, which were not correlated with the quantitative resistance measured in the field. In the adult plant stage the latency period (LP), infection frequency (IF) and colonization rate (CR) were measured in the upper two leaves. The LP was much longer than in the seedling stage and differed strongly between cultivars. The differences in IF were too large, those in CR varied much less. The components showed association with one another. The LP and IF were well correlated with the AUDPC (r = 0.7–0.8). †Deceased     

Predicting transgressive segregants in early generation using single seed descent method-derived <Emphasis Type="Italic">micro-macrosperma</Emphasis> genepool of lentil (<Emphasis Type="Italic">Lens culinaris</Emphasis> Medikus)

In a self-fertilised crop like lentil, the identification of transgressive segregants for economically important trait such as seed yield is an important aspect of any practical breeding programme. The prediction of expected transgressive segregants in F₁ generation obtained as a ratio of additive genic effect [d] and additive variance (D) i.e. [d]/√D was studied in 28 crosses of lentil generated in a diallel fashion involving four parents each of macrosperma (exotic) and microsperma (Indian) types, respectively, resulting in three hybridization groups. The seed material advanced to F₂, F₃ and F₄ generations through single seed descent method was evaluated to determine the observed transgressive segregants for seed yield/plant. The observed frequency of crosses showing more than 20% transgressive segregants in F₂ to F₄ generations were exhibited in 9(32%) crosses, of which 7(77%) crosses were of macrosperma × microsperma type. Genotypes Precoz and HPL-5 of the exotic group (macrosperma) produced maximum number of transgressive segregants with the genotypes L-259, L-4145 and PL-406 of the Indian origin (microsperma). Goodness of fit (non-significant χ² value) in F₂ generation was observed for 19(68%) crosses of the total genepool, out of which 9(56%) crosses each in F₃ and F₄ generation belonged to the macrosperma × microsperma group, depicting it as the gene pool of paramount importance to obtain maximum transgressive segregants, therefore establishing the efficacy of the method used.     

Die Wurzelentwicklung von Zuckerrübenpflanzen auf einem Sandlöß-Standort und ihre Bedeutung für die Stickstoffernährung

Root development of sugar beet plants on a sandy loess site with regard to nitrogen nutrition.
Root development of sugar beet plants in a sandy loess soil (Haplic Phaeozem) was observed from the early seedling stage up to harvest by measuring at first the greatest vertical and lateral extension of the root systems of single plants and later the rooting density of the whole plant stands (auger method, profile wall method).
During the seedling stage not only the subsoil, but also large parts of the topsoil between the plants remained unoccupied by the root systems. In this phase the greatest lateral extension of single roots reaches nearly the length of the greatest leaf of the plant. With the closure of the canopy the rooting density in the topsoil accounts to 1–2 cm cm⁻³.
In summer roots penetrate to a depth of 100–150 cm with rooting densities of 0.1 to 1 cm - cm⁻³. Thus, the plants gain not only access to water reserves, but sometimes meet remarkable amounts of nitrate which under the relatively dry conditions of the region tends to accumulate in 60–120 cm depth and – when taken up by the beet plants in the late stage of growth – affects crop quality negatively.