Changing allele frequencies associated with specific resistance genes to leaf blast in backcross introgression lines of Khao Dawk Mali 105 developed from a conventional selection program

Key genomic regions associated with blast resistance against a broad spectrum of isolates could be identified in backcross introgression lines developed by conventional breeding program. In this article, eighty three BC₃F₂ backcross introgression lines (BILs) derived from a cross between IR68835-98-2-B-2-1-1 (a broad spectrum blast resistance variety) and KDML105 (a susceptible variety) were developed by phenotypic selection against a mixture of six virulent blast isolates (MXL) that are widely spread out in the rainfed lowland of the North and Northeast of Thailand. The resistance spectrum of the BILs was assessed by inoculating with 12 different Magnaporthe oryzae isolates that showed differential responses on the parental cultivars and the MXL that was used for phenotypic selection. All BILs showed highly resistant reactions (low disease score) to the MXL and to two blast isolates THL48 and THL149. Four markers, i.e., RM246, RM241, RM303 and RM164 completely favoring the IR68835 allele (shifting of allele frequencies from KDML105 to IR68835) were identified on chromosomes 1, 4 and 5, respectively. Therefore, these markers could be linked to the resistance genes functioning against the MXL, THL48 and THL149. Furthermore, significant shifting of alleles was identified at six markers located on chromosomes 2, 4, 8, 9 and 12. Seven DNA markers linked to specific resistance genes were identified, in which allele from IR68835 at 6 markers, i.e., RM6, RM205, RM211, RM252, RM273 and RM342 reduced disease score (DS), against blast isolates THL16, THL329, THL458, THL831, THL868 and THL96036 while allele from KDML105 at RM208 (Pi-kd on chromosomes 2) reduce DS against THL84, THL191, THL557 and THL1108. In this study, the use of DNA markers enabled the identification of specific resistance genes in the backcross breeding materials developed from routine rice breeding program through the conventional phenotypic selection. In this experiment, the usefulness of breeding materials from conventional breeding program in identifying genes corresponding to the selection was illustrated. Linked markers and their genomic location provide necessary information for further use of marker-assisted selection to improve blast resistance in rice breeding program.     

Biological and chemical evaluation of chick pea seed proteins as affected by germination,extraction and α-amylase treatment

The effects of germination, extraction (double extraction with 70% ethanol and water at isoelectric point) and -amylase treatments of chick pea seed flours on crude protein, total carbohydrate, protein efficiency ratio (PER), biological value (BV), true digestibility (TD), net protein utilization (NPU), essential amino acid composition, in-vitro protein digestibility (IVPD) and actual amino acid indices (essential amino acid index or amino acid score) were evaluated. Crude protein content was increased (8–149%), while total carbohydrate was decreased (11–62%) by germination, extraction and -amylase treatments. Alpha-amylase treatment was more efficient in reducing total carbohydrate and increasing the protein content than that of extraction treatment. The protein quality of chick pea flours as measured by PER, BV, TD, NPU, IVPD and corrected amino acid indices (actual amino acid indices×IVPD) was significantly improved by these treatments. The protein quality of germinated--amylase treatment was comparble with casein, while germinated--amylase treaded seeds appeared nutritionally superior to casein. The results indicate that the germinated--amylase and germinated--amylase-extracted treatments could be used successfully as a source of concentrated high quality protein for baby food production. The corrected amino acid indices gave better prediction of PER, BV, TD and NPU (r=93 to 97) than actual amino acid indices (r=45 to 71). PER was highly correlated with corrected amino acid score (r=0.93). The PER could be predicted from the following simple regression equation: PER=–1.827+0.0561×corrected amino acid score.     

Fatty Acid Composition of Serum,Adipose Tissue,and Liver in Rats Fed Diets Containing Corn Oil or Cottonseed Oil

There have been few studies on the effect of cottonseed oil (CSO), one of the most commonly used vegetable oils in the United States, on indices of lipid status either in the rat or in any other species. Previous studies with rats have focused on the effect of CSO, versus that of other vegetable oils, on the concentration of cholesterol in serum and liver or on a limited number of fatty acids in serum, adipose tissue, or liver. The present study was designed to compare more fully than in previous studies the effect of CSO to that of corn oil (CO) on the fatty acid composition of serum, adipose tissue, and liver. Two groups of male rats (n=10 each) were used, each fed one of two purified diets containing 100 g/kg of either CO or CSO. Between-group differences included higher values (mol% total fatty acids) in adipose tissue for palmitic acid and stearic acid, but lower values in serum, adipose tissue, and liver for cis-vaccenic acid and oleic acid (C18:1n-9) for the CSO group than the CO. In addition, values in serum, adipose tissue, and liver for -linolenic acid (C18:3n-3) and its metabolite, docosahexaenoic acid (C22:6n-3), were lower for the CSO group than the CO. There was no effect of diet on serum or tissue levels of n-6 fatty acids (linoleic acid, dihomo--linolenic acid, and arachidonic acid). Differences in fatty acid compositions noted, e.g., those for C18:1n-9 and C22:6n-3, mainly reflected compositional differences between the two oils. Thus, use of CSO rather than CO affected serum and tissue concentrations of saturated, monounsaturated, and n-3 polyunsaturated fatty acids (PUFAs) but had no effect on n-6 PUFA status.     

Analyzing genotype by environment interaction in potato using yield-stability index

The plant breeding program of the National University of Colombia carried out 10 potato regional trials during 1998 and 1999 to evaluate 15 promising potato clones (Solanum tuberosum ssp.andigena). Genotype by environment interaction was analyzed using Kang’s methodology, which links yield performance and phenotypic stability. A MACRO was implemented using the SAS system to obtain yield-stability indices. Shukla’s variance was estimated by restricted maximum likelihood (REML), which allowed handling unbalanced data for both genotypes and replicates. In addition, a multivariate analysis methodology was developed, based on the yield-stability index. This methodology is useful when tuber yield is categorized by size and quality, which is usual in Colombian potato harvests.     

大豆分子标记及辅助选择育种技术的发展

分子标记、QTL的研究和辅助选择应用已经得到很大的发展,一批与大豆形态性状、产量性状、品质性状、生态性状、抗生物胁迫性状相关的QTL在国内外均有报道.但近年来分子标记和QTL研究在比较发达的国家已经转向功能标记(FMs:EST-SSR、SNP和候选基因)的研究,相继肩动大豆EST计戈呼和大豆功能基因组计划,以期使功能基因和性状直接联系起来,目前已经取得了显著成效.而我国目前分子标记和QTL的研究还主要集中在利用随机标记(RMs:RAPD、SSR和AFLP)对性状进行研究.该文就国内外大豆分子标记和分子标记辅助育种及分子育种技术发展动态和发展中存在的主要问题做一概述.     

Breeding Wheat for Improved Milling and Baking Quality

Abstract

The molecular determinants of flour functionality and the targeted end-uses for flour define the methods used for improving wheat (Triticum aestivum L.) quality. We review major biochemical systems (gluten, grain hardness, starch, pentosans, lipids, and pigments) affecting wheat milling and baking quality. In early segregating generations (Fj to F₄), breeding programs select for the basic criteria that define a market class (e.g., grain hardness, color, kernel shape, and gluten strength). When desired and possible, improvement of highly heritable traits (e.g., PPO, GBSS mutations, and glutenin sub-units) in early generations is practiced through selection for desired seed or molecular phenotype. In advanced generations (F₅ to cultivar release), bake tests and rheological measures identify breeding lines fitting the subtle characteristics of a market class. Breeding programs favor rapid measures of end-use quality to rank breeding lines for relative end-use quality rather than time consuming protocols that would precisely measure the rheology of flour. Integration of genetic, biochemical, and rheological factors with breeding goals and realistic selection protocols results in the improvement of end-use quality for new cultivars of wheat.     

Selection indices for improving selection efficiency in Indian mustard

In Indian mustard (Brassica juncea L. Czern & Coss), a major oilseed brassica crop, oil yield is the ultimate trait of economic value, which is determined by seed yield (SY) and oil content (OC). SY, the end product of many complex biological processes, is influenced by many traits, such as plant height (PH), branch number, siliqua number, seed weight, seed size and pod length. It is difficult to accurately select for high-yielding genotypes based exclusively on SY, neglecting other yield-determining traits in commercial breeding programs. Therefore, it is desirable for breeders to simultaneously improve several traits of economic importance, most of which are quantitative in nature. The purpose of the present study was to develop selection indices for simultaneous selection of multiple quantitative traits to enhance selection efficiency of the mustard breeding program of Punjab Agricultural University (PAU) located in Abohar, Punjab. A set of 487 diverse mustard genotypes, comprising germplasm accessions of Indian and European origin, advanced breeding lines, landraces, and cultivars, was evaluated using an alpha lattice design for 2 years (2015–16 and 2016–17) at the Regional Research Station of PAU, Abohar, District Fazilka (the major mustard-growing region of the Punjab state). Data on PH, main shoot length (MSL), number of primary branches (NPB), number of secondary branches (NSB), number of siliquae on main shoot (NSMS), siliqua length (SL), number of seeds per pod (NSP), 1000-seed weight (TSW), SY on a plot basis and OC were recorded. To compute selection indices, economic weights, as determined via path coefficient analysis, were assigned to major yield-determining traits. Out of eight recorded agronomic traits, four traits, viz., NSMS, TSW, NSB and NPB, had larger direct effects on SY than other traits, and hence were assigned relative economic weights of 0.60, 0.20, 0.12 and 0.08, respectively. Selection indices were computed using different combinations of traits via Kang_SASPath computer program. When seven traits were used in a selection index (PH, NPB, NSB, NSMS, SY, TSW and MSL; or PH, NPB, NSB, NSMS, SY, TSW and OC), expected genetic advance (GA)at 5% selection intensity was about the same (9.55; selection efficiency or SE = 163% compared with selection based on SY alone).The GA was 9.46 (SE = 161%)for five traits, viz., NPB, NSB, NSMS, SY and TSW; and 9.30 (SE = 159%)for four traits, viz., NPB, NSB, NSMS, and TSW. These GAs were compared with the GA for SY only, which was 5.90 (benchmark; SE = 100%). We concluded that simultaneous selection based on multiple traits was always more efficient than selection based on SY alone. As there was only a small difference between the GA based on four traits (SE = 161%) and GA based on seven traits (SE = 163%), we suggest that mustard breeders use the parsimonious combination of four traits, viz., NPB, NSB, NSMS, and SY, to enhance SY and, consequently, oil yield in mustard.     

亚麻优异种质创新利用及发展

亚麻种质创新工作采用外源总体DNA导入,Co60-γ射线处理种子、植株以及利用雄性核不育材料进入转育等方法创造新类型、新材料,提供给育种家,培育出一批优异亚麻新品种,促进了亚麻生产的飞速发展.随着新的生物技术和信息技术的突破,对今后种质创新工作进行展望.     

Use of Selection Indices Based on Multivariate Analysis for Improving Grain Yield in Rice

In order to study selection indices for improving rice grain yield, a cross was made between an Iranian traditional rice (Oryza sativa L.) variety, Tarommahalli and an improved indica rice variety, Khazar in 2006. The traits of the parents (30 plants), F1 (30 plants) and F2 generations (492 individuals) were evaluated at the Rice Research institute of Iran (RRII) during 2007. Heritabilities of the number of panicles per plant, plant height, days to heading and panicle exsertion were greater than that of grain yield. The selection indices were developed using the results of multivariate analysis. To evaluate selection strategies to maximize grain yield, 14 selection indices were calculated based on two methods (optimum and base) and combinations of 12 traits with various economic weights. Results of selection indices showed that selection for grain weight, number of panicles per plant and panicle length by using their phenotypic and/or genotypic direct effects (path coefficient) as economic weights should serve as an effective selection criterion for using either the optimum or base index.     

Sensory evaluation as a tool in breeding potatoes for French fries and flakes

Standardized sensory evaluation of advanced breeding clones developed in the research program of the Horticulture Department at North Dakota State University has been conducted annually since 1980. Procedures used by the USDA-ARS Potato Research Laboratory for processing tubers into partially fried french fries or flakes are described along with the procedures used for finish-frying of the fries and rehydrating the flakes in preparation for sensory evaluation in the Food and Nutrition Department at North Dakota State University. Following brief training, panelists evaluate the fries and flakes from each clone in triplicate for color, flavor, and texture. Procedures for determining length of fries and limpness of fry strips are described. Samples of 334 clones prepared as french fries and 135 clones prepared as flakes have been evaluated. Examples are given of types of data collected with interpretation of results in relationship to their use in the breeding program.     

蔬菜育种的三向选择策略及其定量化实施方法初探

在分析现有蔬菜育种技术的特点和杂种优势育种中存在的问题的基础上,从杂种优势育种中自交系的选育理论和国内外的蔬菜育种实践中,概括、总结出蔬菜育种的三向选择策略,即基于从选育出的材料直接应用于目前的新品种育种实践的目标考虑,在对一基本材料的分离世代(如F2代)进行选择时,除以对照品种为依据,按有性杂交育种途径经多代选择选育出新品种外,还可按照杂种优势育种目标中对母本、父本的要求,经多代选择选育出母本自交系、父本自交系。实践中,三向选择策略的实施方法有定性法和定量法2种,但定量法能更大程度地提高育种效率,将更受育种者的青睐。初步从遗传上探讨了三向选择策略在杂种优势育种中的两种定量化实施方法:1)以对照品种为依据,2)以杂种优势预见性育种理论为依据。这2种定量化实施方法,均解决了亲本自交系的选择指标定量化这一难题,从而可以定向选育亲本,提高了杂种优势育种的预见性和育种效率。      

Evaluation of physiological traits as indirect selection criteria for drought tolerance in sugar beet

Drought is the most important limitation to sugar beet (Beta vulgaris L.) production in the UK and other areas dependent on usually insufficient summer rainfall. As increased irrigation is not a viable answer to the problem, an economically and environmentally desirable solution is new varieties with decreased sensitivity to water deficits. However, there is little genotypic information on drought tolerance in sugar beet, and breeders are not equipped to make these selections. The objectives of this study were to assess the degree of genotypic diversity for drought-related morpho-physiological traits and to measure the strength of association between these traits and indicators of crop performance. 46 sugar beet genotypes with diverse genetic backgrounds were tested in three field experiments from 1999 to 2001. Drought was imposed by covering plots with large polythene tunnels, allowing the crop to grow solely on stored soil moisture. Agronomic characters and drought tolerance indices are described in a companion paper [Ober et al., Assessing the genetic resources to improve drought tolerance in sugar beet. Agronomic traits of diverse genotypes under droughted and irrigated conditions. Field Crops Res., in press]. In this report, we show that there were significant genotypic differences for stomatal conductance, succulence index, specific leaf weight, and osmotic adjustment, but not for photosynthetic rate, relative water content or total water use. Patterns of water use within the soil profile differed between genotypes; some extracted more water from deep soil layers. The maintenance of green foliage cover during drought was positively correlated with drought tolerance index, which was negatively correlated with succulence index and scores for wilting and leaf senescence. Droughted sugar yield was positively correlated with soil water extraction and negatively correlated with relative leaf expansion rate measured in late summer. Under irrigated conditions, there was high positive correlation between transpiration rate and sugar yield. Genotype × trait biplots showed superior genotypes with relatively greater expression of combinations of favourable traits. The results suggest that succulence index and wilting score could be used to cull inferior plants in early stages of breeding programs, and green foliage cover and patterns of water use could help identify superior genotypes in elite germplasm. These data should enable tools to be developed for indirect selection of genotypes suited to drought-prone environments.     

水稻氮素生理利用率选择参数（英文）

 将植株从衰老营养体转运氮到产量部分的效率定义为水稻氮素生理利用率，其选择参数根据单位吸收氮的产量及从衰老营养体转运氮到产量部分的能力具有较高预期响应确定。在盆栽试验条件下测定100个F₂植株的单位吸收氮产量（G/Nt）、产量（G）、收获指数（HI）、收获期秸秆氮浓度（SN%）及稿秆氮含量（SN）。结果表明，G/Nt，G及HI与SN%及SN呈显著的负遗传相关。由HI，G，SN%及SN构成的三个选择参数的通径分析表明，HI，G，SN%及SN在选择参数中直接效应大干间接效应。由HI和SN%及G，SN%和SN构成的选择参数对G/Nt的预期响应高于以G/Nt本身为参数的选择并与G/Nt高度相关。     

中国水稻育种百年发展与展望

水稻是中国最重要的口粮作物,新品种的培育与推广对水稻生产作出了重大贡献。中国现代水稻育种起步于20世纪20年代,已有百年历程,期间纯系育种、杂交育种、诱变育种和分子育种等技术成为技术主体,成就了矮化育种、杂交稻育种和超级稻育种三次突破,推进了全国水稻平均单产从20世纪50年代的200 kg/667 m²平台跃上了当前的470 kg/667 m²平台。展望未来百年的水稻产业需求,培育C4水稻、固氮水稻、耐盐碱水稻、耐旱水稻和一系杂交稻是水稻育种面临的重大任务。     

Verbreitung des Wissens über die ‘innere’ Qualität von Gemüse und Obst in der Öffentlichkeit

Zusammenfassung Anhand praktischer Beispiele werden qualitätsrelevante Problemkreise vorgestellt und eingehend diskutiert, so Erzeugerberatung — Weg der Ware vom Erzeuger zum Verbraucher — Äußere Beschaffenheit — Innerer Wert — Präsentation der Verkaufsware — Erhaltung der Frische — Berücksichtigung ernährungsphysiologischer Kriterien. Es wird ein Publikationsmodell — bereits 1950 entwickelt — vorgeschlagen, das weite Kreise der Züchter, der Erzeuger, der Fabrikanten, des Handels und der interessierten Verbraucherschaft sowohl ansprechen als auch das Verständnis der einzelnen Gruppen untereinander wecken könnte.Denn letztlich sollte es doch im Bermühen des Erzeugers, des Transporteurs, des Handels, des Verarbeiters von Obst und Gemüse in erster Linie darum gehen, das Wohlergehen, die Gesunderhaltung des Verbrauchers im Auge zu haben. Das wäre jedenfalls die Vorstellung und Erwartung der ernährungsphysiologisch und ernährungs-hygienisch ausgerichteten Qualitätsforscher.

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Public extension about the inner Quality of Vegetables and Fruit

As usually practized in vegetable and fruit cultivation problems relevant to the inner quality are presented and discussed, e.g. Information of consumers, Shipping products from producer to consumer, External Quality — inner Quality — Offering of products — Conserving of freshness — Regarding the nutritional value.In order to evaluate these problems a close co-operation of breeders, producers, manufacturers, dealers and the interested consumers seem to be necessary. This is possible through a model and system of information, similar to the so-called AZA which were first published in 1950.

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Referat, gehalten auf der Sitzung der neukonstituierten Kommission Öffentlichkeitsarbeit der DGQ am 1.10.1976 in Geisenheim/Rhein.     

Studies on weaning diets in Nigeria: 2 protein sources

Protein isolates were extracted from melon, groundnut, and soybean cakes in an aqueous system that could potentially yield both oil and protein from oilseeds quantitatively. Protein isolates obtained were 91.2, 78.6 and 79.5% of the total protein content of melon, groundnut and soybean cakes respectively. Both cakes and isolates were assessed in a rat bioassay while breadfruit, cassava, and corn starch were also investigated as sources of carbohydrate. Results showed that there were no significant differences between feed intake, weight gain and PER of rats fed the cake and the protein isolates except in soybean. Weight gain, PER and NPR were highest in cassava-soybean protein isolate diet followed by cassavacasein diet (control) while performance was only moderate with melon- and groundnutcassava diets. With melon protein isolate, cassava and breadfruit were better carbohydrate sources than corn starch. In simulated weaning diets, cassava-sucrose-melon-soybean protein isolate based diet performed better (weight gain 33.4 g, PER 1.63, NPR 2.23) than a commercial weaning food (weight gain 30.6 g PER 1.57, NPR 2.18) while replacement of sucrose and cassava at 30% by breadfruit yielded a cost effective diet with good performance (weight gain 29.4 g, PER 1.51, NPR 2.12). Diets where soybean protein served as the sole source of protein or breadfruit, white and yellow maize ogi served as the main source of carbohydrate performed only moderately.     

Crop Breeding in the Twenty-First Century

SUMMARY

One can predict a future in which professional plant breeding, especially in the private sector, will be significantly scaled back, and advanced biotechnologies (e.g., genetic engineering) will be forbidden for use in plant breeding. Alternatively, one can predict a future in which commercialism will rule all sectors. But a more optimistic outlook predicts that the current tripartite division of responsibilities will prevail: Private Sector, Public Sector, and Participatory (i.e., farmer-breeder partnerships). The global plant breeding system is composed of separate organs, each essential for the survival of the whole but each with a different function. All parts work together for the good of the whole.     

Development of molecular simulation methods to accurately represent protein-surface interactions: The effect of pressure and its determination for a system with constrained atoms

When performing molecular dynamics simulations for a system with constrained (fixed) atoms, traditional isobaric algorithms (e.g., NPT simulation) often cannot be used. In addition, the calculation of the internal pressure of a system with fixed atoms may be highly inaccurate due to the nonphysical nature of the atomic constraints and difficulties in accurately defining the volume occupied by the unconstrained atoms in the system. The inability to properly set and control pressure can result in substantial problems for the accurate simulation of condensed-phase systems if the behavior of the system (e.g., peptide/protein adsorption) is sensitive to pressure. To address this issue, the authors have developed an approach to accurately determine the internal pressure for a system with constrained atoms. As the first step in this method, a periodically extendable portion of the mobile phase of the constrained system (e.g., the solvent atoms) is used to create a separate unconstrained system for which the pressure can be accurately calculated. This model system is then used to create a pressure calibration plot for an intensive local effective virial parameter for a small volume cross section or "slab" of the system. Using this calibration plot, the pressure of the constrained system can then be determined by calculating the virial parameter for a similarly sized slab of mobile atoms. In this article, the authors present the development of this method and demonstrate its application using the CHARMM molecular simulation program to characterize the adsorption behavior of a peptide in explicit water on a hydrophobic surface whose lattice spacing is maintained with atomic constraints. The free energy of adsorption for this system is shown to be dramatically influenced by pressure, thus emphasizing the importance of properly maintaining the pressure of the system for the accurate simulation of protein-surface interactions.