Research on the Genetic Resources of Inulin-Containing Chicory (Cichorium intybus)

Chicory has potential as a new industrial crop. However, root chicory seems to have a limited generic basis which might hamper breeding progress. The objective of the investigation was (i) TO assess the yield potential of chicory and (ii) to ascertain whether leaf chicory might be suitable to broaden the genetic basis of root chicory breeding. Forty-nine accessions of leaf and root chicory were cultivated in field trials. Root yield/plot varied between 15.0 kg and 22.6 kg (experiment 1) and 14.8 kg and 27.0 kg (experiment 2). Total sugar content ranged between 15.2–21.8 % and 14.5–22.9 %. The corresponding values for total sugar yield are 2.32–4.12 kg and 2.38–5.45 kg. Fructose/glucose ratios ranged from 6.59 to 9.76 and 4.20 to g.22 depending on experiment and accession. Estimated on a plot oasis the highest total sugar and fructose yield was achieved by ‘Fredonia’ (10.6 t/ha and 9.5 t/ha, respectively). In addition, correlation coefficients between yield components were estimated. The correlation coefficients between total sugar content and total sugar yield ranged from, r = 0.62–0.78. The results suggest that leaf chicory may not contribute to a rapid breeding progress in root chicory within a short period.     

Genetic variation, heritability and progeny testing in meadow bromegrass

Meadow bromegrass is a recently introduced pasture grass in western Canada. Its leafy production and rapid regrowth have made it a major grass species for pasturing beef animals in this region. Because relatively little breeding work has been done on this species, there is little information on its breeding behaviour. The main objective of this study was to estimate genetic parameters and assess breeding methodologies for meadow bromegrass. Forty half‐sib (polycross and open‐pollinated) and full‐sib (selfed) progenies were evaluated for dry matter and seed yield, fertility index, harvest index, plant height, plant spread, crude protein, neutral detergent fibre and acid detergent fibre. Genetic variation for seed yield, harvest index, and plant height was significant in the open‐pollinated and selfed tests. Genetic variation estimates for dry matter yield were negative (polycross), not significant (open‐pollinated), or significant (selfed). Estimates of genetic variation for quality traits were not significant, except for acid detergent fibre (selfed). Correlations among characters indicated that it is possible to simultaneously improve seed and forage yield. Rankings of progenies by the half‐sib tests for forage and seed yield were not altered by the use of the synthetic parental value (SV_i), which includes information from selfed progeny. The polycross progeny test did not discriminate parents as well as the open‐pollinated and selfed tests; this may have been a result of non‐random pollination in the polycross. Correlation among the progeny tests, showed that open‐pollinated and selfed progeny tests agreed for all characters, except for harvest index, while correlation between polycross and selfed tests were significant for six characters but not dry matter yield, and acid and neutral detergent fibres. The most dissimilar tests were polycross and open‐pollinated, with significant correlations found only for fertility index, height, spread and neutral detergent fibre. It was concluded that there was significant variation and moderate heritability for most traits in the meadow bromegrass populations evaluated, and that the open‐pollinated progeny test is the method of choice for selecting parents for synthetics of this species.     

Drought tolerance variability in S<Subscript>1</Subscript> pollinator lines developed from a sugar beet open population

Drought tolerance is one of the most important objectives of sugar beet breeding programs in semi-arid regions, particularly during the last decade. Due to global climate changes and limitations of agricultural irrigation water, varieties with drought tolerance are taken into consideration in order to avoid yield losses due to drought. In this study, drought tolerance of 76 S₁ lines (full-sib families) that had been extracted from a genetically broad base multigerm sugar beet open pollinated population, were examined. Test crosses were made between the lines as pollinators and a cytoplasmic male sterile (CMS) single cross. The consequent hybrids along with checks were evaluated during 2007 and 23 more tolerant hybrids during 2008, in two adjacent experiments under drought stress and non-stress conditions. Drought tolerance indices calculated based on sugar yield, such as mean productivity (MP), geometric mean productivity (GMP) and stress tolerance index (STI) were used to assess hybrids responses to drought. The results showed significant genetic differences for root yield and sugar yield under both conditions. Drought tolerance indices displayed significant genetic variability for sugar yield among the hybrids. Many hybrids were drought tolerant as compared with the original base population as indicated by their high STI. The estimates of heritability for sugar yield in stress and non-stress conditions were much close to each other (0.31 and 0.34, respectively). Whereas, for root yield the heritability estimate in stress condition (0.46) was relatively higher than that in non-stress condition (0.34). Significant differences were observed among the selected hybrids for root yield and sugar yield, indicating genotypic variability for pollinator lines derived from the population. There were no significant differences for sugar content. For increasing the drought tolerance potential in a breeding population and developing drought-tolerant varieties by male parent, the drought-tolerant lines could be used.     

A Study of Fructose Yield Components in Chicory

2557 chicory roots from 13 cultivars were analysed individually for root weight, root shape, total fructose, total glucose, potassium and amino-N contents. Fructose yield is highly correlated with root weight and slightly with fructose content, both at the inter- and intra-varietal levels. The comparison of total-sample correlations to between- and within-variation correlations suggests an important genetic variation within varieties.     

Variability of Yield Characters and Selection in Solanum ladniatum Ait.

The steroid bearing medicinal plant, S. laciniatum, was bred for high solasodine yield for commercial cultivation in Thailand. Starting materials for breeding consisted of seven populations of different origin. Variability among these populations was examined using an unselected control population cultivated over three years. Additive and dominance variance were estimated from a polycross and diallel mating design. Significant genotypic variability was found for solasodine concentration, height of the plants, and total shoot length, promising successful selection for the most important yield characters. Additive variance and heritability in the narrow sense were low for all yield characters, due to previous selection of the parental plants used for the polycross and diallel mating. No dominance effects could be found for any of the characters. In conclusion, breeding S. laciniatum for quantitative yield characters by selection will be superior to hybrid breeding. As a result of selection, significant increases in the most important yield characters in the offspring of selected populations were obtained.     

Selection for combining ability in Pyrethrum,Chrysanthemum cinerariaefolium Vis.

Summary Pyrethrum is grown for the insecticidal pyrethrins, present mainly in the flowers. It is a cross-fertilizing perennial which can be propagated vegetatively. The main selection criteria are fresh flower yield and pyrethrins content; important secondary criteria are flower size and resistance to lodging; dry matter content varies very little.For these traits, the breeding values (general combining ability) of 22 clones were determined by means of a polycross. The heritabilities were estimated from the regressions of the polycross progeny data on those of the female parent clones; these were: flower yield 0.31; pyrethrins content 0.70; flower size 0.80 and resistance to lodging 0.87. For dry matter content no correlation between parents and progenies could be measured. Independent heritability estimates, obtained from 33 single crosses between clones not represented in the polycross, were: flower yield 0.56; pyrethrins content 0.64. Of 18 single crosses, made between clones also represented in the polycross, the actual flower yields and pyrethrins contents were highly correlated with the estimated yields and contents which were calculated from the breeding values of the parent clones (r = +0.87 and +0.86, respectively).These data show that the performance of single crosses is caused predominantly by the general combining ability of the parent clones. Therefore, single crosses offer no fundamental advantages over synthetic varieties, so that, for practical reasons, the latter are preferred. At the same time it is recommended to practise reciprocal recurrent selection as this will exploit the general combining ability in the initial stages of selection and the specific component increasingly in later selection cycles.Published with the approval of the Director of Agriculture, Kenya.     

The efficiency of between and within full-sib family selection in a recurrent selection programme in sugar beet (Beta vulgaris L.)

The efficiency of between and within family selection in a full-sib family recurrent selection programme was investigated using data from three cycles of recurrent selection. Correlations between mid-parent values and offspring were high for sugar content and juice purity characters, but low for root weight and sugar yield. This suggests that single root selection within full-sib families is effective in the improvement of sugar content and juice purity, but ineffective for root weight and sugar yield. Root weight and sugar yield will respond better to between full-sib family selection. This revised version was published online in July 2006 with corrections to the Cover Date.     

Root traits and yield in sugar beet: identification of AFLP markers associated with root elongation rate

Morpho-physiological and molecular analysis were conducted to identify useful root indexes of sugar beet nutrient uptake capacity and productivity. Root architectural parameters, root elongation rate, sulfate uptake rate and glucose and fructose content in the root apex, traits involved in the plant response to sulfate stress, were evaluated in 18 sugar beet genotypes characterized by different root yield. Morpho-physiological traits, determined on 11-day-old seedlings grown in hydroponics under sulfate deprivation, showed variations from 59 to 197% and were significantly correlated (P < 0.01) with root yield. Under field conditions, the highest root yield genotype (L18), which has the highest root phenotypic values following sulfate shortage, also showed the greatest root length density and leaf relative water content, with respect to the lowest root yield genotype (L01). Bulk segregant analysis based on AFLP analysis, done on a segregating progeny obtained from the cross between the two lines L01 × L18, allowed the identification of two AFLP markers associated to the root elongation rate parameter that showed the highest variation among all the analyzed root traits. The genetic diversity of root adaptive traits and the use of marker-assisted selection aimed at increasing sugar yield under water and nutrient stress in sugar beet breeding programmes are discussed.     

Selective Absorption of K over Na in Sugar Beet Cultivars and its Relationship with Yield and Quality in Two Contrasting Environments of Central Greece

Selective absorption (SA) of K over Na (i.e. the preferential absorption of K over Na) has been proposed as a Na tolerance mechanism but genotypic variation for this trait has not been assessed with sugar beet in the field. Thus, the aim of this study was to explore the variation of SA in 14 sugar beet cultivars and to relate SA with yield and root quality in two sites of central Greece (Amfithea and Pyrgetos). Genotypic variation for SA was significant and the SA values were higher in Pyrgetos, the site with the lower soil K and Na concentrations. In Pyrgetos, a favourable environment for sugar beet growth, cultivars yielded more and root quality was better. In that site, a negative relationship between SA and yield (fresh root weight, sugar yield) was found indicating that strong Na exclusion from root is a disadvantage for high yielding. Negative SA–yield relationships were evident in Amfithea when five cultivars with very low SA values (<1.00) were excluded from the analysis. Combined all the cultivars, curvilinear functions were the best-fitted curves for the SA–yield relationships. In Amfithea, where sugar beets had lower water content in root (WCR), a significant, positive correlation between SA and % sucrose content in fresh root weight was found. This finding was ascribed to the dilution of sucrose in roots due to the increased WCR as a result of the increased root Na concentration. In both sites, SA was positively related with root K concentration and negatively with Na concentration. The positive correlations between SA and root α-amino N concentration indicated that sugar beet N nutrition could be affected by the genotypic ability to exclude Na from the root.     

Impact of different environments in Europe on yield and quality of sugar beet genotypes

Sugar beet (Beta vulgaris L.) yield and quality are determined by genotype and environment. This study aimed at analysing the relative importance of the environment for yield and quality of sugar beet genotypes and at assessing parameters which could give essential improvement for beet quality if included as additional selection criteria. For that purpose, root yield and quality (sugar, K, Na, amino N, total soluble N, betaine, glutamine, invert sugar, raffinose) of 9 sugar beet genotypes were investigated in 52 environments (25 sites in 2003 and 27 sites in 2004) in randomised field trials across Europe.The environment accounted for about 80% of the total variance for all parameters. Effects of the tested genotypes were larger for the content of betaine (8.5%) and sugar (7.6%) than for other parameters (1–5%). With the exception of invert sugar and amino N, the genotype by environment interaction was about 3% and thereby lower than the main effect of genotypes. Interactions resulted in an increase of the differences between genotypes which can be used to select genotypes in the most discriminating environments. The response of genotypes in sugar content was contrasting to other parameters and points to a physiological limit for sugar storage at about 20%. As no crossover interaction occurred for root yield or any quality parameter, there seemed to be no specific suitability of the tested genotypes to certain environmental stress conditions. This is probably due to the fact that the harvested beetroot is a vegetative storage organ and has no growth stages susceptible to unfavourable environmental conditions such as flowering and grain filling which are important for final yield in cereals. Invert sugar showed the largest relative differences between genotypes which were strongly enhanced in southern and some south-eastern European environments. Because of its importance during processing, considering invert sugar in breeding could improve technical quality for processing considerably for those extreme environments.     

Adaptive Responses of Beta Vulgaris L. and Cichorium Intybus L. Root and Leaf Forms to Drought Stress

Plants respond to drought with a restriction of leaf and root growth. The study aimed at analysing the morphological and functional adaptation mechanisms of Beta and Cichorium storage root and leaf forms to limited water supply. Two pot experiments were conducted: (i) with sugar beet, swiss chard, root and leaf chicory at 100 %, 50 % and 30 % water supply, (ii) with sugar beet, fodder beet and swiss chard at 100 % and 30 % water supply. The results indicate that there is no general response mechanism of root and leaf forms to better sustain drought stress. Sugar beet adapted to limited water supply with a marked decrease in the storage root to leaf ratio, indicating in particular a restriction of the predominant sink, while maintaining a very low transpiration coefficient. In contrast, swiss chard, root and leaf chicory kept their storage root to leaf ratio almost constant while adapting the transpiration coefficient. Sucrose storage was inversely related to the accumulation of solutes in the storage root of sugar beet and fodder beet. There is some evidence that the formation of a storage root in sugar beet and root chicory is inhibited by the inability of the plants to establish new sink capacities under drought conditions.     

The phylogenetic relationship between different Cichorium intybus cultivars and cultivar groups, as revealed by RAPDs

The phylogenetic relationship between different Cichorium intybus cultivars and cultivar groups was studied. A total of 127 random amplified polymorphic DNA markers have been used to distinguish between 51 Cichorium intybus cultivars belonging to three different cultivar groups. A principal component analysis was performed on the complete data set and a clear grouping of chicory cultivar groups was observed. The three chicory groups tested (root chicory, witloof and pain de sucre) were separated from one another in the principal component plots. The first two axes accounted for 43.9% of the total variation. Although the chicory used in traditional forcing in soil and the red chicory cultivars were related more to each other and to the chicory cultivars from the witloof group, they still formed separate groups in the principal component plot.     

Genotype selection for physiological responses of drought tolerance using molecular markers in polycross hybrids of orchardgrass

The present study aimed to assess the effect of contrasting levels of molecular and phenotypic diversity among polycross parents of orchardgrass on the performance of synthetic progeny with respect to physiological responses and drought tolerance. Four polycross groups each composed of six parental plants were evaluated under normal irrigation and drought stress conditions. A number of 923 inter simple sequence repeats and sequence related amplified polymorphism markers and several phenotypic traits were used to select contrasting levels of diversity (high and low) in parental genotypes. Highly significant correlation was observed between molecular distance and progeny performances at both normal irrigation and drought stress conditions. High molecular diversity among polycross parents led to a significant yield advantage of first generation progeny with averages of 34.40% for normal irrigation and 48.10% for drought stress conditions. Also crosses between genetically distant parents produced progeny with considerable drought tolerance and yield stability. Positive associations between phenotypic distance of parents and progeny performance were found for most physiological traits at both moisture regimes but phenotypic distances had weak association with forage yield, stress tolerance index and yield stability of progeny. Significant associations between drought tolerance index and some physiological traits confirmed the importance of these traits in conferring drought tolerance of orchardgrass. Our results underscore the effectiveness of marker‐assisted polycross breeding to improve drought tolerance and yield stability through physiological traits in orchardgrass.     

不同引进甜菜品种经济性状关系分析

为了探究不同甜菜品种块根重量、大小、长度之间的差异性,以及甜菜块根个体和含糖率、块根产量和含糖率之间的关系,以5个新疆主栽甜菜品种(KWS1176、KWS9147、BETA379、BETA468、BETA356)为材料,用GB/T 10496-2018中的调查方法测定5个甜菜品种的块根性状、含糖率、根产量和产糖量等经济性状,并分析其相关性。KWS1176、KWS9147、BETA379、BETA468、BETA356之间单个块根重量差异性不显著。块根含糖率表现为：KWS1176(13.62%)> BETA379(13.37%)> BETA468(12.80%)>KWS9147(12.56%)> BETA356(9.04%);块根产量表现为：KWS9147(100000.5 t/hm2)> BETA468(95000.48 t/hm2)> BETA379(93187.97 t/hm2)> BETA356(89875.45 t/hm2)>KWS1176(82000.41 t/hm2)。KWS1176、KWS9147、BETA356含糖率与个体...     

木薯主要农艺性状的遗传变异、相关性和主成分分析

对广西14个主要木薯品种的9个农艺性状进行了遗传变异分析、相关性分析和主成分分析。结果表明,块根长,块根鲜重、块根数的变异系数较大,分别为13.95%、11.33%、10.22%,块根干物质率和茎径的变异系数最小,分别为7.00%和6.57%;在相关性上,产量与块根数呈极显著的正相关,块根干物质率与块根淀粉含量呈极显著的正相关;主成分分析结果表明,前4个主成分对变异的贡献率达85.69%。在性状选择上,首先对变异大的性状进行选择是非常重要的。在品种选择时,应注意选择产量和淀粉含量均高的品种。     

Assessment of breeding progress in sugar beet by testing old and new varieties under greenhouse and field conditions

Breeding has led to a continuous increase of the performance of sugar beet varieties and thereby contributes to meet the global needs for food and biomass. This study aimed to analyze the extent of the breeding progress in sugar beet and to determine which parameters and traits were modified by breeding. In 2007 and 2008 sugar beet varieties registered between 1964 and 2003 were cultivated in field trials and in greenhouse experiments to exclude effects from changes in agronomic operations and climatic conditions. Differences in white sugar yield related to the reference variety registered in 1964 were regarded as breeding progress. The results showed an increase in the white sugar yield of 0.6–0.9% a⁻¹ from 1964 to 2003 due to breeding. This was achieved by an improved biomass partitioning (higher root to leaf ratio and higher sugar to marc ratio), better technical quality (decreased concentration of K, Na, and amino N combined as standard molasses loss) and enhanced assimilation (higher chlorophyll content, higher assimilation rates). No changes were observed in leaf development and cambium ring formation. A principle component analysis pointed out that breeding targets have shifted with time from “yield” to “biomass quality”. To continue the breeding progress in future it is essential to integrate multiple resistances and tolerances against biotic and abiotic stress.     

Comparison of predicted and observed response to selection in two breeding populations of perennial ryegrass

To predict any genetic response to selection, two breeding populations of perennial ryegrass, consisting of half-sib families, were evaluated as spaced plants from 1987 to 1989 for several agronomical traits. In each population, the best plants selected through a multitrait Smith and Hazel's index were planted in a polycross to produce the second generation half-sib families. Both generations were evaluated together from 1991 to 1993 as spaced plants. The difference between generations was the observed genetic response, which was compared to that predicted. Rust tolerance, aftermath heading and persistence were significantly improved in both populations. In trial plots used to assess the yield, no effect of mass selection was noticed. Thus, it is concluded that mass selection failed to increase productivity but produced some improvements in disease tolerance and aftermath heading.     

Quantitative genetics in an apple breeding strategy

Summary Open-pollinated seed of 500 genotypes of commercial cultivars, breeding selections and wild species of apples (Malus × domestica) was collected from overseas mixed-clone repositories. This is to generate the first generation of the new Apple Breeding Population.Subsequent generations will be intercrossed in a pair-crossing design. Recurrent selection for general combining ability (GCA) is the breeding method used for genetic improvement of the Breeding Population. Every parent in the control-pollinated breeding population is tested for GCA using a polycross mating design.The best individuals of the Breeding Population, intensively selected between families using the polycross GCA estimates, and also within families are intermated to produce a Cultivar Production Population. Trees selected from this have then to be evaluated in grafted clonal tests before commercial release.Each generation, a new Breeding Population of 500 genotypes is selected from the pair-cross families, based on parental GCA values (from polycross tests), full-sib family means and individual performance and then intercrossed. Greatest emphasis will be on within-family selection not between-family, so as to avoid reducing the effective population size.     

甜菜种质资源品质性状鉴定与评价

旨在更加科学真实地评价甜菜种质资源的品质性状,有针对性地对种质资源优异品质性状进一步挖掘利用。引用甜菜块根蔗糖可回收率、杂质指数、可回收蔗糖量3 个综合指标,排除甜菜块根中有害性非糖分钾、钠、α-氮的影响,对参试的162 份甜菜种质资源2 年试验鉴定结果的有关品质性状进行分析。结果表明：甜菜块根中影响蔗糖提取的有害性非糖分钾、钠、α-氮在不同的种质资源材料间差异较大,其中钠含量在参试种质资源材料中极差达到4.763 mmol/100 g,为平均数的1.84 倍,变异系数34.43%;α-氮含量和钾含量在不同参试种质资源材料间也表现出较大差异,变异系数分别为16.90%和19.03%。通过对参试种质资源材料的评价,筛选出蔗糖含量高、有害性非糖分含量低的高糖组种质资源材料10份、中高糖组48份材料,2组平均蔗糖可回收率分别为15.88%和14.95%;筛选出杂质指数低于4.0、块根产量在45.00 t/hm2以上的丰产型种质资源材料7份,杂质指数4.0~4.5、块根产量在45.00 t/hm2以上丰产性较好的种质资源材料14 份。甜菜块根中可回收蔗糖量指标综合了蔗糖可回收率和块根产量2个性状指标,利用该项指标评价种质资源材料,可以挖掘出丰产优质的种质资源。用可回收蔗糖量指标评价甜菜品种,筛选丰产、高工艺品质的品种,兼顾甜菜种植者和制糖企业双方利益,有利于甜菜制糖产业可持续发展。     

基于响应面法优化低糖菊苣根干加工工艺的研究

以新鲜菊苣根为试材,采用单因素试验及响应面试验,结合模糊数学感官评价法,以色差和感官评分为考察指标,筛选合适的护色方法,探究真空渗糖时间、真空度和CMC-Na添加量对低糖菊苣根干的影响,并优化低糖菊苣根干加工工艺参数。结果表明:采用1%NaCl溶液护色,真空渗糖时间为210 min,真空度为0.02 MPa,CMC-Na添加量为0.86%的工艺条件制得的低糖菊苣根干感官性状最佳,色泽透亮,口感清甜,形状饱满,具有菊苣根特有的香气。