Genetic variability and interrelationship among various morphological and quality traits in quinoa (Chenopodium quinoa Willd.)

Evaluation of seed yield, morphological variability and nutritional quality of 27 germplasm lines of Chenopodium quinoa and 2 lines of C. berlandieri subsp. nuttalliae was carried out in subtropical North Indian conditions over a 2-year period. Seed yield ranged from 0.32 to 9.83 t/ha, higher yields being shown by four Chilean, two US, one Argentinian and one Bolivian line. Two lines of C. berlandieri subsp. nuttalliae exhibited high values for most of the morphological traits but were low yielding. Seed protein among various lines ranged from 12.55 to 21.02% with an average of 16.22 ± 0.47%. Seed carotenoid was in the range of 1.69–5.52 mg/kg, while leaf carotenoid was much higher and ranged from 230.23 to 669.57 mg/kg. Genetic gain as percent of mean was highest for dry weight/plant, followed by seed yield and inflorescence length. All morphological traits except days to flowering, days to maturity and inflorescence length exhibited significant positive association with seed yield. The association of leaf carotenoid with total chlorophyll and seed carotenoid was positive and highly significant. The path analysis revealed that 1000 seed weight had highest positive direct relationship with seed yield (1.057), followed by total chlorophyll (0.559) and branches/plant (0.520). Traits showing high negative direct effect on seed yield were leaf carotenoid (−0.749), seed size (−0.678) and days to flowering (−0.377). Total chlorophyll exerted strongest direct positive effect (0.722) on harvest index, followed by seed yield (0.505) and seed protein (0.245).     

Genetic and environmental analysis of NIR feed quality predictions on genotypes of barley (Hordeum vulgare L.)

This study investigated the use of NIR feed quality equations, developed from a multi-cereal calibration set, including barley, on barley breeding lines and commercial cultivars. The resultant predictions were then analysed to ascertain genetic and or environmental affects. The calibrations were developed by a third party, using a NIRSystems 6500 (master) instrument. The barley spectra we used were also from the same model of instrument, which had been spectrally standardised to match the master instrument. The breeding lines and commercial cultivars used were obtained from a field trial series which combined intermediate and advanced breeding lines, grown at 11 environments over two seasons. The results indicated there were significant (P < 0.05) genetic and environmental effects on a broad range of feed quality related traits; including metabolisible energy, digestible energy and apparent metabolisible energy. Other feed traits such as acid detergent fibre, neutral detergent fibre, β-glucan and starch also showed significant (P < 0.05) genetic and environmental affects. There was a high level of heritability for most traits, ranging from 70 to 90%. The results identified a number of strongly correlated traits when analysed by factor analysis. These included starch and the energy traits. There were no strong associations between particular cultivars and the NIR predicted feed traits. The results from this study highlighted NIR equations for predicted feed quality that can provide data to assist selection of barley breeding lines. In addition, the analysis also showed the genetic and environmental effects that could be expected to be observed in a broad range of barley breeding material and commercial varieties. This information can be combined in breeding programs to identify robust barley lines that would be suited to specific animal feed classes.     

甘蓝型油菜杂种优势及产量性状的遗传改良

对不同来源的3个甘蓝型油菜自交不亲和系与22个父本品种的遗传距离及它们以NCII法配制的66个杂交组合的产量、物候期性状进行了分析.结果表明,尽管3个自交不亲和系与父本品种间的遗传差异较小,但它们与国外品种间的杂种F1产量性状平均优势均较强.杂种生育期及初花至成熟期日数均介于双亲之间,但前者偏向晚熟亲本,而后者却偏向早熟亲本.与其它产量构成因子相比,一次分枝及其角果数不仅对单株产量贡献率最大,且对单株产量杂种优势贡献率亦最高.在油菜产量性状的遗传改良中,特别是在杂种优势利用中,首选目标性状应为一次分枝及其角果数.在保证一次分枝及其角果数前提下,提高角粒数、千粒重亦是一条有效途径.     

大豆粒茎比的遗传及其与其它农艺性状的相关研究

本试验是在前人研究基础上,利用未经选择的大豆F3、F4世代为试材,研究大豆粒茎比的遗传及与相关性状的关系,明确粒茎比的遗传规律、选择效果和它在产量选择中的作用,探索在哈尔滨生态条件下,适合的大豆粒茎比类型,为高产育种提供理论依据。大豆粒茎比于F3、F4代呈明显分离,各组合单株粒茎比的次数分布呈为单峰曲线,呈正态分布;大豆粒茎比的遗传是以加性为主的数量性状,早期世代遗传力低,不易选择,随着世代增加,遗传力增大,可在F4代和以后世代进行选择;大豆亲本粒茎比的中亲值与F3、F4代粒茎比的均值呈显著的正相关,中亲值可做为大豆杂交育种中亲本选配的一个指标;大豆粒茎比与植株高度、主茎节数、分支数、分支荚数、生物产量、收获重、茎重呈负相关,与主茎荚数、株粒数、百粒重呈正相关,长叶型株系粒茎比高于园叶型株系粒茎比;有限类型株系高于亚有限类型,说明随着进化程度提高大豆粒茎比值有提高的趋势;大豆粒茎比与单株产量的关系较复杂,在一定范围内大豆粒茎比值的提高产量会提高,超过一定的范围,产量会有所降低。说明在一定生态条件下,都有一定的适应大豆粒茎比类型,粒茎比大小反应了一定生态条件下所形成的生态类型。在哈尔滨田间条件下,大豆粒茎比值在0.9左右的品种类型,可望获得高产。     

Effects of genetic improvements on grain yield and agronomic traits of winter wheat in the Yangtze River Basin of China

Wheat is an important food crop worldwide. Genetic improvements have contributed much to wheat production since the 1960s. Verifying the evolution of agronomic traits and the physiological basis of grain yield will facilitate breeders and agronomists in developing new wheat cultivars, with the aim of stable and high yields. Thirty-five wheat cultivars, bred or widely planted in the Yangtze River Basin from 1950 to 2005, were grown in field experiments under three N rates (0, 112.5, and 225 kg N ha⁻¹) from 2006 to 2009 in Nanjing, China. Wheat grain yield, kernels per spike, 1000-kernel weight (TKW), and harvest index (HI) increased linearly with cultivar development from the 1950s to the 2000s, whereas spikes per unit land decreased significantly with cultivar development during the same period, and stabilized with further genetic improvements in cultivars. Grain yield, kernels per spike, and TKW differed with N rate and with cultivar. Grain yield, spikes per unit land, and kernels per spike increased significantly with increasing N fertilizer, but TKW and HI decreased. Cultivar height decreased with cultivar development from the 1950s to the 1980s, and remained relatively stable in subsequent cultivars. The proportion of the length of the top internode to total plant height increased with cultivar development from the 1950s to the 1980s and thereafter fell, while the length of the basal internode (BI) maintained a shortening trend. Leaf area per culm, leaf area index (LAI), net photosynthetic rate (Pn), and photosynthetic activity duration (PAD) of the flag leaf increased with cultivar development. Leaf area, LAI, and Pn increased significantly with increasing N fertilizer, while PAD did not. Single spike yield increased linearly with genetic development in cultivars, and these increases mainly resulted from increasing kernel number and weight, which were closely related to source size and cultivar. Grain yield was positively correlated to leaf area, LAI, Pn_Max, PAD, and single spike yield; single spike yield was positively correlated to leaf area, LAI, Pn_Max, and PAD, suggesting that grain yield improvements were mainly associated with improvements in the source (leaf area, LAI, Pn, PAD, etc.) and sink (single spike yield). Sink-source ratios increased with genetic development of cultivars, suggesting that productivity per leaf improved and that sink-source relationships have reached close to optimum in the Yangtze River Basin. Furthermore, breeding for high yield should be related to improvement in kernels per spike and TKW per unit land and increased sink-source ratios with a feasible LAI, and N fertilizer management should be considered during breeding for higher yields.     

Analysis on genetic contribution of agronomic traits to total sugar in flue-cured tobacco (Nicotiana tabacum L.)

To uncover the genetic contributions of agronomic traits to content of total sugar (TS) and find indicator traits for indirect selection on TS in the flue-cured tobacco (Nicotiana tobacum L.), multivariable conditional analysis was conducted based on a genetic model containing additive–dominance and their interactions with environments. Fourteen cultivars (or breeding lines) and derived 41 F₁ crosses were grown at four locations in Yunnan province, China. Significant phenotypic contribution to TS was detected for six agronomic traits, plant height (PH), girth of stem (GS), internode length (INL), number of leaves (NL), length of middle leaves (LML) and width of middle leaves (WML). There was large contribution of additive effects due to each of the five agronomic traits (PH, GS, INL, LML and WML). The contribution ratio of dominance effect was high due to PH. By serving as high contributor of additive effects to TS and having high ratios of additive variance to phenotypic variance, INL and PH could be used as indicative agronomic traits for selecting breeding lines with suitable TS. Among the six agronomic traits, PH had the highest contribution to dominance effects of TS for most F₁ crosses, and could be used for selecting the crosses with suitable TS.     

甘蓝型黄籽油菜粒色的遗传分析

采用MINQUE(1)统计方法,以7个不同遗传来源的甘蓝型黄籽品系为材料配制完全双列杂交,用ADM和ADAA模型对粒色进行遗传分析.结果表明,粒色主要受加性和加×加上位性效应控制,母体效应和环境对粒色的影响也很明显.用y1、y2、y3作杂交育种亲本,较易获得黄籽度较高的后代,亲本选配以y1×y2、y1×y3、y2×y6组合粒色最好.     

Genetic variability and diversity for protein and calcium contents in finger millet (Eleusine coracana (L.) Gaertn) in relation to grain color

Analysis of 36 genotypes of finger millet ( Eleusine coracana (L.) Gaertn) with varying seed colors revealed a wide range of protein and calcium contents. White seeded genotypes had higher protein contents, while brown seeded types had a wide range of values. The brown seeded genotype GE 2500 had the highest protein content. Although protein content had significant negative association with calcium content, white seeded types had moderate levels of calcium. The genotypic coefficients of variability were moderate and high for protein and calcium, respectively. High heritability coupled with high genetic advance indicated their governance by additive gene action. A negative significant correlation was observed between protein content and grain yield. Mahalanobis D 2 analysis grouped the 36 genotypes into eight clusters. Clustering pattern failed to indicate any relationship between genetic diversity and geographic diversity. Based on genetic diversity and performance, the genotypes MS 1168, MS 174 and CO 13 were found to be suitable for use as parents in a hybridization program for improving yield; the genotypes MS 1168, MS 174 and MS 2869 for protein and Malawi 1915 and CO 11 for calcium. Protein and calcium contents contributed less to genetic divergence.     

Comparison of fatty acid composition,phytochemical profile and antioxidant activity in four flax (Linum usitatissimum L.) varieties

The present study evaluates variations among flaxseed varities in terms of fatty acid composition, phytochemical profile, and antioxidant activity determined by oxygen radical absorbance capacity (ORAC), 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ferrous ion reducing antioxidant power (FRAP) assays. Significant variations in fatty acid composition, phenolic acids and lignan were observed in flaxseed varieties from different countries. Among them, unsaturated fatty acids accounted over 4/5 of total fatty acid content. The highest ratio of linolenic acid of total fatty acid was observed in USPEA, whereas the lowest one was found in Yexiao. USPEA showed the highest content of total phenolics, as well as flaxseed lignan. In general, total phenolics appeared to be the main contributors of antioxidant capacity of flaxseed, which presented significant positive correlation. Our study revealed that both cultivar and origin of seed significantly affected fatty acid composition, phenolic acids, lignans and subsequent antioxidant activity of flaxseed. These results provided new aspects of breeding resources of flaxseed cultivars by presenting their quality specification and possible commercial value.     

Genetic analysis for resistance to bean fly (Ophiomyia phaseoli) and seed yield among common bean genotypes in a semi-arid environment

Bean fly (Ophiomyia spp.) is a major field pest limiting common bean production in eastern Africa. The genetic enhancement of beans for resistance to insect pests is essential for minimizing yield losses arising from crop damage. The objectives of this study were to (1) assess combining ability for bean fly resistance and seed yield accumulation in common bean and (2) estimate genetic parameters associated with resistance for formulating further breeding strategy. Four parents with known reaction to bean fly were crossed with four locally adapted genotypes in an 8 × 8 half diallel mating design. Parents and F₂ progenies were grown in an alpha-lattice design replicated twice in an open-field and subjected to natural populations of bean fly for two cropping seasons under semi-arid conditions. Similarly, two resistant and two susceptible parents were selected and crossed to produce populations for generation means and variances components analysis. Results revealed that both general combining ability (GCA) and specific combining ability (SCA) mean squares were significant (p ≤ 0.05) for all four traits studied except SCA for stem damage during one cropping season. Among the parents, GBK 047858 was the best general combiner for all the traits studied across seasons except for stem damage during long rains (LR) 2009. Besides, genotypes GBK 047821 and Kat × 69 (a locally adapted variety) were generally good general combiners for resistance traits as well as seed yield. General predictability ratio (GPR) values ranging from 0.63 to 0.90 were obtained for plant mortality, stem damage, pupae in stem and seed yield across cropping seasons. These results established the predominance of additive gene effects (fixable variation) over the non-additive effects in controlling the traits. Low to moderate narrow sense heritability values ranging from 0.22 to 0.45 were obtained for pupae in stem. Such heritability estimates indicate that although additive gene components were critical in the inheritance of resistance for the trait, non-additive gene action were also important in addition to the environmental effects.     

Correlation studies on 1000-true-seed weight,tuber yield and other morphological traits in potato (Solanum tuberosum L.)

Summary Simple phenotypic, genotypic and environmental correlation coefficients were calculated from one year's data for nine characters in F₁ seedlings of 72 crosses and 18 parents of potato (Solanum tuberosum L.). Crosses were made in a line x tester model having 12 female lines and six male testers. The experiment was designed as a randomized block replicated three times at Kufri, Simla (India) during the 1979–80 crop season. Positive phenotypic and genotypic correlations of 1000-TPS weight were found with total tuber yield, number of leaves on the main shoot, number of shoots per plant and harvest index. The results suggest that 1000-TPS weight could be used when attempting to select for yield and other characters in F₁ seedlings. Adapted from a thesis submitted and approved for the degree of Doctor of Philosophy of Agra University.     

Estimation of genetic variability in locally grown pulses (Cajans cajan (L.) Millsp and Vigna unguiculata (L.) Walp): a panacea for sourcing superior genotypes

The negligence of breeders and farmers to explore and exploit landraces of pulses is worrisome and urgent measures needed to be set in motion to forestall major future crisis, taking into cognizance the high adaptability and nutritive values accredited to them. This study focused on the estimation of genetic variability and heritability of desirable morphological characters in Fiofio (Cajans cajan) and Olaudi and Akidi (Vigna unguiculata) with the aim of conservation. Three landraces of pulses were sown using randomized complete block design. The field experiment was carried out at the University of Calabar Experimental Farm, University of Calabar, Calabar, during 2008-2010 growing season. Phenotypic and genotypic variances and coefficients of variation and genetic advance were estimated on yield and yield-related traits. The results showed that there were considerable variations among the pulses for the traits studied. The result revealed high genetic variability in the number of leaf per plant, leaf area, number of flowers per plant, number of pods per plant and number of seeds per plant. It also showed that genetic variability in pod length and 100-seed weight was low. Heritability estimates obtained in the result were very high though the magnitude of genetic variability in the yield and yield-related traits was not proportional to the heritability estimates. The traits studied also show high genetic advance. These explicitly showed that there are sufficient genetic variations to warrant conservation and improvement in these extinction-threatened pulses studied.     

Influence of agronomic factors on yield and quality of hemp (Cannabis sativa L.) fibre and implication for an innovative production system

Research and development of an innovative production system for hemp (Cannabis sativa L.) fibre for textile use requires the integration of multidisciplinary knowledge from cultivation technique to realization of end products. Research was carried out to study the effect of the agronomic factors cultivation year (2003–2004), genotype (Futura 75 and Tiborszallasi), plant population (120, 240 and 360 plants m⁻²) and harvesting time (beginning and full flowering) on fibre yield and quality in the whole hemp stem, and in the basal and apical stem portions separately. The study of separate stem portions was done to determine the effect on fibre quality of an innovative harvesting and processing system in which hemp stems are cut in two portions of approximately 1 m at harvest to enable processing on modern flax scutching lines.     

Measurement of genetic and environmental variation in barley (Hordeum vulgare) grain hardness

In this study, we assessed a broad range of barley breeding lines and commercial varieties by three hardness methods (two particle size methods and one crush resistance method (SKCS—Single-Kernel Characterization System), grown at multiple sites to see if there was variation in barley hardness and if that variation was genetic or environmentally controlled. We also developed near-infrared reflectance (NIR) calibrations for these three hardness methods to ascertain if NIR technology was suitable for rapid screening of breeding lines or specific populations. In addition, we used this data to identify genetic regions that may be associated with hardness. There were significant (p<0.05) genetic effects for the three hardness methods. There were also environmental effects, possibly linked to the effect of protein on hardness, i.e. increasing protein resulted in harder grain. Heritability values were calculated at >85% for all methods. The NIR calibrations, with R² values of >90%, had Standard Error of Prediction values of 0.90, 72 and 4.0, respectively, for the three hardness methods. These equations were used to predict hardness values of a mapping population which resulted in genetic markers being identified on all chromosomes but chromosomes 2H, 3H, 5H, 6H and 7H had markers with significant LOD scores. The two regions on 5H were on the distal end of both the long and short arms. The region that showed significant LOD score was on the long arm. However, the region on the short arm associated with the hardness (hordoindoline) genes did not have significant LOD scores. The results indicate that barley hardness is influenced by both genotype and environment and that the trait is heritable, which would allow breeders to develop very hard or soft varieties if required. In addition, NIR was shown to be a reliable tool for screening for hardness. While the data set used in this study has a relatively low variation in hardness, the tools developed could be applied to breeding populations that have large variation in barley grain hardness.     

Genetic architecture, inter-relationship and selection criteria for yield improvement in rice (Oryza sativa L.)

This study has been conducted to determine the extent of genetic association between yield of Rice (Oryza sativa L.) and its components. The present experiment was carried out with 40 Rice (Oryza sativa L.) genotypes which were evaluated in a randomized block design with 3 replications during wet season of 2007 and 2008. Results showed that sufficient amount of variability was found in the entire gene pool for all traits studied. Higher magnitude of genotypic and phenotypic coefficients of variation was recorded for seed yield, harvest index, biological yield, number of spikelets per panicle, flag leaf length, plant height and number of tillers indicates that these characters are least influence by environment. High heritability coupled with high genetic advance as percent of mean was registered for seed yield, harvest index, number of spikelets per panicle, biological yield and flag leaf length, suggesting preponderance of additive gene action in the expression of these characters. Grain yield was significantly and positively associated with harvest index, number of tillers per hill, number of panicle per plant, panicle length, number of spikelet's per panicle and test weight at both genotypic and phenotypic levels. Path coefficient analysis revealed that harvest index, biological yield, number of tillers per hill, panicle length, number of spikelets per panicle, plant height and test weight had direct positive effect on seed yield, indicating these are the main contributors to yield. From this study it may be concluded that harvest index, number of tillers per hill, panicle length and number of spikelet per panicle and test weight are the most important characters that contributed directly to yield. Thus, these characters may serve selection criteria for improving genetic potential of rice.     

甘蓝型油菜产量性状的遗传及相关与通径分析

以7个不育系和4个恢复系为材料,采用增广NCⅡ交配设计进行油菜4个产量性状的遗传及6个产量构成因子间的相关与通径分析,结果显示：(1)油菜千粒重的遗传符合加性—显性模型,单株有效角果数、角粒数和单株粒重的遗传符合加性—显性—上位性模型。(2)育种上应在保持较多角粒数的前提下,提高千粒重,适当控制单株有效角果数,减少分枝尤其是二次分枝进而提高单产。     

Multivariate analysis and genetic diversity for morphometric and root textural quality traits in ashwagandha (Withania somnifera Dunal)

Ashwagandha (Withania somnifera) is an important medicinal plant and its dried roots are used in traditional systems of medicine. The market price of roots is determined by physical (textural) quality. Brittle roots with high starch and low fiber are considered to be superior because of ease in grinding. Genetic diversity studies based on root textural parameters have not been done so far. So the present study was designed to assess genetic diversity for morphometric traits and root textural quality parameters among two morphologically distinct groups: Poshita and Nagore. The PCA separated the morphometric and root texture variables distinctly into two different principal components: PC-1 and PC-2 respectively, indicating that both are negatively associated. All the morphotypes in Poshita group showed high positive loadings in PC-1 indicating that component genotypes are high root yielding. Nagore morphotypes were low yielding but the root texture was good. Clustering of morphotypes grouped Poshita and Nagore separately with high inter-cluster distances indicating that both groups are highly divergent from each other, suggesting that there is sufficient scope for varietal improvement through hybridization.     

Genetic control of pre-heading phases and other traits related to development in a double-haploid barley (Hordeum vulgare L.) population

Extending the phase of stem elongation (SE) has been proposed as a tool to further improve yield potential in small-grain cereals. The genetic control of pre-heading phases may also contribute to a better understanding of phenological traits conferring adaptability. Given that an optimized total time to heading is one of the most important traits in a breeding program, a prerequisite for lengthening SE would be that this and the previous phase (leaf and spikelet initiation, LS) should be under different genetic control. We studied the genetic control of these two pre-heading sub-phases (from sowing to the onset of stem elongation, LS, and from then to heading, SE) in terms of Quantitative Trait Loci (QTL) in a barley double-haploid population derived from the cross Henni × Meltan, both two-rowed spring North European barley cultivars. DH lines (118) and their parents were studied in four field trials in North-Eastern Spain. Genetic control of a number of traits related to leaf appearance and tillering dynamics, which could be important for an early crop canopy structure, were also studied. LS and SE are, at least partially, under a different genetic control in the Henni × Meltan population, mainly due to a QTL on chromosome 2HS. The QTLs responsible for a different control of LS and SE did not seem to correspond with any major gene reported in the literature. Moreover shortening LS, so as to lengthen SE without modifying heading date, would not necessarily imply a negative drawback on traits that could be important for early vigour, such as phyllochron and the onset of tillering.     

Genetic analysis,realized heritability and synergistic suppression of indoxacarb resistance in Phenacoccus solenopsis Tinsley (Homoptera: Pseudococcidae)

Cotton mealybug Phenacoccus solenopsis Tinsley (Homoptera: Pseudococcidae) has caused huge crop and economic losses in different countries of the world including Pakistan. Considering P. solenopsis as a key cotton pest, research was conducted to understand genetics, realized heritability and preliminary mechanism of indoxacarb resistance. As a result of selection with indoxacarb, P. solenopsis developed a 2223.13-fold resistance after five generations. Indoxacarb resistance was autosomal in nature, and the degree of dominance for F₁ and F₁′ was 0.60 and 0.62, respectively, indicating the incomplete dominance of indoxacarb resistance. A monogenic model of inheritance also showed the involvement of multiple loci in indoxacarb resistance in P. solenopsis. Realized heritability for indoxacarb resistance was markedly high (h² = 1.13) in P. solenopsis suggesting how quickly resistance can develop as a result of selection. Synergism tests with piperonylbutoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) also suggested that indoxacarb resistance in P. solenopsis was metabolism-based due to possible involvement of both mono-oxygenases and esterases. Hence, it was concluded that indoxacarb resistance in P. solenopsis was autosomal, incompletely dominant, polygenic and metabolism-based. These findings will be helpful in the management of P. solenopsis.     

红麻杂种一代及其亲本的遗传组成与配合力分析

以13份红麻品种按NCⅡ（NorthCaralina）6×7交配设计组配42个杂种F1代与其亲本为材料,研究了红麻杂种一代及亲本材料9个主要经济性状的遗传构成及配合力,结果表明：除干皮精洗率外,其它8个性状组合间差异均达显著或极显著水平;遗传变异系数、遗传力、遗传进度均以单株子皮重、单株纤维重等产量性状较高,其余性状相对较低;南选、ID40、84K114－2等亲本一般配合力较好;84210×南选,ID40×917等组合具有高的特殊配合力,表现为强优势组合。