Selection Among Early Generation Peanut Progeny for High and Low Acetylene Reduction and Plant Weight*

Selection of superior host genotypes in symbiosis with native Bradyrhizobium has been suggested as a means of increasing nitrogen fixation m peanut (Arachis hypogaea L.). In this study progeny from a cross of cultivars ‘Florigiant’ and ‘Florunner’ inter-mated twice and selected for yield formed the base population. The 44 selected S_2,1 families, ‘Florigiant’ and ‘Florunner’ were evaluated at two sampling dates at each of two locations for traits indicative of nitrogen fixation. Five families were selected in each of four selection groups — high and low acetylene reduction and high and low plant weight. Selected families were retested in a second year and inter-mated. S_2,1 progeny within each selection group were bulked and evaluated for nitrogen-if using characteristics at two ‘sampling dates at two locations. After intermating, the mean of the high acetylene reduction group, 62.9 μ/moles C₂H₄/plant hr, was Significantly greater than the mean of the low acetylene reduction group, 52.5 μmoles C₂H₄/plant/hr, and of the mid-parent, 55.8 μ/moles C₂H₄/plant/hr. The associated estimate of realised heritability was 55 ± 08 indicating the response to selection was approximately halt the selection differential and that the distinction between families selected for high and low acetylene redaction was maintained after intermating. However, the realized heritability estimate obtained from the means of the base population and the selected families inbred one generation was .14 ± .06 indicating a failure to maintain distinct groups after one generation of inbreeding. The utility of early generation selection for enhanced N: fixation is, therefore, doubtful in this population. Selection based on plant weight was not effective. A significant difference in the plant weight means of the high and low plant weight groups was not detected when selections were retested or after inter-mating. Plant weight was not a useful indirect selection criterion for enhanced N₂ fixation.     

Variability among advanced gamma-irradiation induced large-seeded mutant breeding lines in the 'Georgia Browne' peanut cultivar

The objective of this study was to compare the variability among advanced large‐seeded ‘Georgia Browne’ mutant breeding lines induced by γ‐irradiation. Seeds of the small‐seeded, high‐yielding, disease‐resistant peanut cultivar ‘Georgia Browne’ were exposed to a 200 Gy dose of γ‐radiation. Several advanced (M_6:7–M_6:9)‘Georgia Browne’ mutant breeding lines were developed and evaluated at the University of Georgia, Coastal Plain Experiment Station over three consecutive years 1997‐99 for disease incidence, pod yield, total sound mature kernels (TSMK) grade, pod weight, seed weight and seed size distribution. Field performance tests showed significant differences among the advanced large‐seeded mutant breeding lines compared with ‘Georgia Browne’ for each of these variables. The results obtained demonstrate the beneficial use of mutation breeding for inducing and developing variable and desirable advanced mutant breeding lines within peanut cultivars.     

Genotype-environment interactions and phenotypic stability analyses of linseed in Ethiopia

Seed yield of 10 linseed genotypes, tested in a randomized block design with four replications across 18 environments of Ethiopia was analysed using different stability models. The objectives were to assess genotype‐environment (G‐E) interactions, determine stable genotypes, and to compare the stability parameters. Year by location and location variability were the dominant source of interactions. The stability analyses identified ‘R12‐N10D’, ‘Chilalo’ and ‘P13611’ב10314D’ as more stable genotypes, while ‘R11‐N1266’, ‘R10‐N27G’ and ‘R12‐D24C’ were specifically adapted to some environments. The highly significant rank correlations found among the deviations from regression, additive main effects multiplicative interaction, stability values, coefficients of determination, and stability variances indicated their close similarity and effectiveness in detecting stable genotypes over a range of Ethiopian environments.     

Variation in progenies of an Arachis hypogaea x diploid wild species hybrid

Summary Derivatives of a cross between cultivated peanuts, Arachis hypogaea L. (2n=40), and the wild species collection GKP 10017 (2n=20) were compared morphologically, for leafspot resistance and for yield. The objective of the study was to determine the effects of wild species germplasm on the A. hypogaea genome. The sterile F₁ hybrid which resulted from crossing the two species was treated with colchicine to restore fertility at the 6x ploidy level. The resulting hexaploid was cytologically unstable and progeny lost chromosomes until stability was regained at the 2n=40 chromosome level. Forty-seven characters were used to analyze the variation among plants in the tetraploid interspecific hybrid population. The plants were compared to four cultivated lines plus GKP 10017. Many hybrids were intermediate to the two parents in morphology. Individual traits such as growth habit, pod and seed size, elongation of the constricted area between pods, nodulation and leaflet size were altered by the presence of GKP 10017 germplasm in many of the hybrid plants. Cercospora arachidicola Hori and Cercosporidium personatum (Berk. & Curt.) Deighton resistances were evaluated for all plants. Several hybrids had few lesions due to either leafspot pathogen. In addition, 24 largeseeded interspecific hybrid selections were compared to the cultivated variety NC 5 for yield. Five selections were superior to both parents at p=0.01. Morphology, disease resistance and yields appeared to be greatly influenced by the wild species GKP 10017 germplasm in plants of the interspecific hybrid population. The potentials of using wild species for improvement of the cultivated peanut are discussed.Paper number 5948 of the journal series of the North Carolina Agricultural Research Service, Raleigh, NC 27650. The investigation was supported in part by ICRISAT and SEA-CR grant no. 701-15-51.     

江苏花生新品种鉴定和产量稳定性分析

为了准确、客观地评价江苏花生新品种鉴定试验参试品种（系）的特征特性,促进江苏花生新品种的推广应用,采用高稳系数法分别对淮南、淮北组的12个参试品种（系）进行丰产性和稳产性分析,并进行品质、抗性及主要农艺性状调查。结果显示：各参试品种均具有中等以上的耐旱性、耐涝性、叶斑病及锈病抗性。具体来说,淮南组的‘宁泰9922’产量较高,且稳产性较好;‘苏花0537’种皮深红色,熟期早,适应性广,粗蛋白含量较高;淮北组的‘连1001’、‘赣榆10-6’、‘东花9号’及‘徐0627’分别较对照‘徐花13号’增产4.7%~7.4%,同时产量稳定性优于对照。因此认为以上品种可以进一步示范和推广应用,同时也表明用高稳系数法评价花生品种（系）的高产稳产性是可行的。     

花生品种在巴州地区复播的综合评价

为筛选适宜在新疆巴音郭楞蒙古自治州复播种植的花生品种,在巴州地区复播种植6个花生品种,采用灰色关联度分析方法对10个农艺性状进行综合评价,并分析产量与各农艺性状的相关性。结果表明,综合评价中,各花生品种的等权关联度与加权关联度排列位次一致,排列位次为‘吉花4号’>‘四粒红’>‘DF05’>‘远杂9102’>‘DF06’>‘闽花6号’。‘吉花4号’综合性状评价优于对照‘四粒红’,适宜在新疆巴州地区复播条件下推广种植。而花生‘DF05’、‘远杂9102’、‘DF06’、‘闽花6号’的综合农艺性状劣于对照‘四粒红’,不建议推广种植。相关分析表明,产量与出仁率呈显著正相关。研究结果为巴州地区引进花生高产品种提供了材料基础和理论依据。     

砂姜黑区施肥水平对花生不同基因型品种产量和品质的影响

【目的和方法】采用大田裂区随机区组设计试验,研究了施肥水平对花生不同基因型品种产量和品质的影响,为豫南花生主产区砂姜黑土上花生高效施肥提供技术支撑。【结果】结果表明,花生不同基因型品种的农艺性状、经济性状和产量存在明显的差异,常规施肥条件下,远杂9102、远杂6和豫花22的产量分别为5958.1kg/hm2、5437.1kg/ hm2、6008.6kg/ hm2,比不施肥分别增加18.4%,14.9%和13.7%;施肥能提高远杂9102、豫花22花生仁中油酸含量、油酸/亚油酸的比值,降低远杂6花生仁中油酸含量、油酸/亚油酸的比值;花生不同基因型品种对花生仁中粗脂肪含量及产量有明显的影响,远杂6花生仁中粗脂肪的含量最高,粗脂肪的产量最小,平均分别为50.3%、1873.3 kg/hm2,豫花22花生仁中粗脂肪的含量最低,粗脂肪的产量最高,平均分别为48.6 %、1895.2 kg/hm2。【结论】在N、P2O5、K2O施用量分别为150 kg/hm2、90 kg/hm2、150 kg/hm2条件下,豫花22的荚果产量和粗脂肪产量均最高,分别为6008.6 kg/hm2和2059.7 kg/hm2。     

Assessment of sweet cherry (<Emphasis Type="Italic">Prunus avium</Emphasis> L.) genotypes for response to bacterial canker disease

Integration of alleles for bacterial canker resistance into new sweet cherry cultivars requires information on the sources of resistance in the germplasm. Five market-leading sweet cherry cultivars, ‘Rainier’, ‘Sweetheart’, ‘Bing’, ‘Regina’ and ‘Chelan’, advanced selections ‘AA’, ‘BB’, ‘CC’, ‘DD’, ‘EE’, ‘GG’, and ‘PMR-1’ used as breeding parents in the Washington State University’s Sweet Cherry Breeding Program were evaluated. Comparative genotypic disease severity was obtained with three methods of inoculation (leaf wounding with carborundum, cut wounds in leaf mid-rib and shoot tip) on whole plants. Additionally, genotypic data on susceptibility of detached leaves versus fruit and an assessment of the movement of Pseudomonas syringae pv. syringae (Pss) population in inoculated shoots were obtained. Genotype susceptibility was significantly (P ≤ 0.05) influenced by inoculation method, with shoot inoculation providing the best separation of resistance levels among genotypes. A low correlation (r = 0.26, P = 0.21) was observed between disease responses measured on detached leaf versus fruit, while a moderately high correlation (r = 0.50, P = 0.10) was found among bacterial populations in the tissues and in the degree of symptoms expressed. By all comparative methods, the advanced selections, as well as, ‘PMR-1’, were less susceptible than the market-leading cultivars. Also, movement of Pss from shoot tip inoculation points to the shoot base was not detected for advanced selections ‘AA’, ‘BB’, ‘DD’, and ‘EE’. This study reveals that the advanced selections could be potential sources of resistance alleles to bacterial canker. This is the first evaluation of the advanced selections for bacterial canker disease.     

Natural occurrence of autopolyploidy within the allotetraploid-cultivated peanut

The cultivated peanut is classified as an allotetraploid species. During the past several years, abnormal plants with coarse stems, thick leaves and an occasional single seed per pod have been found within different cultivars and advanced breeding lines. The spontaneous natural occurrence of these plants has been very rare, and frequently they do not produce any pods or seed. However, over a 3‐year period (2001–2003), four individual plant selections with one mature seed per plant were found and saved. In 2003, another similar plant was also found that had the same plant characteristics, except for a single branch that had normal leaves with typical two‐seeded pods. A greenhouse study was conducted during the winter of 2003–2004. The four coarse stem individual plant selections from the previous years were planted along with the check cultivar ‘Georgia Green’ and the sectorial plant found in 2003. S₁ seed from both the one‐seeded pods as well as normal two‐seeded pods were planted from the sectorial plant. Relative DNA content was measured by flow cytometry on all plants. Results from the test showed that the coarse stem, thick leaf plants with poor fruit set were autooctoploids and had about twice the DNA content when compared with the normal sectorial branch and the allotetraploid peanut cultigen.     

Heterozygous genotypes are efficient testers for assessing between-population combining ability in the reciprocal recurrent selection of Coffea canephora

Coffea canephora Pierre breeding in Côte d’Ivoire is based on indirect reciprocal recurrent selection (RRSi) using the Congolese and Guinean populations. In practice, the genotypes of each population (78 Congolese genotypes and 100 Guinean genotypes) are tested with several testers from the reciprocal population: two Guinean and three Congolese testers. These testers are heterozygous as C. canephora is a strictly outcrossing species. After a first cycle of RRSi, we judged the efficiency of these testers for yield, susceptibility to coffee leaf rust (SCLR) and hundred bean weight (HBW). All the testers discriminated the tested genotypes highly significantly (P < 0.01), even though differences were found in the degrees of discrimination. For yield and SCLR, no interaction between tested genotypes and testers was observed and correlations between test values obtained from different testers were significant or highly significant. Furthermore, test values of tested genotypes could be used to predict the yield and SCLR of between-population (BP) hybrids. Prediction was always more accurate with the best tester than with the mean of several testers. As opposed to yield and SCLR, HBW showed significant interactions between tested genotypes and testers and HBW of hybrids could not be predicted from the test value of the genotypes. We conclude that only one reciprocal tester can be used in the next cycles of RRSi applied to C. canephora. This will allow either a reduced cost of selection or increased selection intensity.     

Location-Specific and Across-Location Selections for Seed Yield in Populations of Common Bean, Phaseolus vulgaris L.

Two populations of common bean, Phaseolus vulgaris L., were used to make three independent location-specific selections at Palmira, Quilichao, and Popayán, Colombia. Also, three across-location selections were made by alternating generations between Palmira and Popayan, between Quilichao and Popayán, and among Palmira, Quilichao, and Popayán. The seven highest yielding lines selected from each environment and population along with 14 parents and two checks were evaluated for seed yield, seed weight, maturity, and reaction to an-thracnose, angular leaf spot, and common bacterial blight. Mean squares due to evaluation and selection environments, selected lines, and their interactions were significant for all traits. Mean yields of selected lines were higher than the mean of parents in both populations. Among location-specific selections, lines yielded higher at their respective selection site. Moreover, selections made at Popayán were higher yielding than those made at Quilichao or Palmira when tested across locations and years. Use of Popayán, a relatively wetter and cooler site, either alone or in combination with other locations resulted in higher yield, higher seed weight, and higher resistance to anthracnose. On the average, location-specific selections were lower yielding than the across-location selections. Among across-location selections, those selected between Palmira and Popayán were the highest yielding in both populations. Selections at Palmira and across all three locations resulted in greater stability.     

施氮量对花生产质量及氮肥利用率的影响

采用大田裂区随机区组设计试验,研究了施氮量对不同品种花生产质量和氮肥利用率的影响,以期为豫南砂姜黑土区花生高产优质和氮肥高效利用提供合理的施氮依据。研究结果表明,随着施氮量的增加,不同花生品种荚果产量均呈增加趋势,施氮量为180 kg/hm2时,豫花23、远杂9102和远杂6的花生产量均最高,分别比不施氮的增产30.45%、25.96%和21.46%;随着施氮量的增加,豫花23花生仁中蛋白质含量和粗脂肪含量均呈抛物线变化趋势,而远杂6和远杂9102花生仁中蛋白质含量呈增加趋势,粗脂肪含量呈降低趋势;除了施氮降低远杂6和远杂9102花生仁中蛋氨酸含量外,施氮均能增加其他花生蛋白质组分的含量;远杂9102的氮利用率最高,为36.7%;豫花23的农学效率和氮肥偏生产力均最大,分别为6.9 kg/kg和36.9 kg/kg。本试验条件下,豫花23、远杂6适宜的施氮量为180kgN/hm2,花生产量分别为5330.36 kg/hm2、5002.98 kg/hm2,远杂9102适宜的施氮量为135 kgN/hm2,花生产量为5199.40 kg/hm2。     

Frequencies of Vertical Resistances and Virulences in the Rye-Powdery Mildew Pathosystem*

Nine populations of rye (Secale cereale L.; the cultivars ‘Kustro’, ‘Danko’ and ‘Carokurz’. a breeding population PA 14/75 and five Iranian primitive ryes) were tested with three or two pathotypes of powder)’ mildew (Erysiphe graminis DC. f. sp. secalis Marchal) to determine the frequencies of vertical resistances. Similarly, three populations of powder)’ mildew isolated from the above eultivars were tested with two rye pathodemes to estimate the frequencies of vertical virulences. Tests were carried out on leaf segments cultivated in vitro. To explain the pattern of the host-parasite interaction, a model with at least four resistance and virulence genes was required. In the rye populations the genotypes of most plants could be determined unambiguously whereas in the powdery mildew populations no unique classification of one-postule isolates was possible due to the limited number of rye differentials. Both the host and the pathogen populations were polymorphic for resistance and virulence, respectively. In all lye populations except PA 14/75 the resistance frequencies were low. In the mildew populations the virulence frequencies were high and complex races occurred rather frequently. The virulence frequencies were related to the resistance frequencies of the respective host population. Results were compared with mathematical host-parasite models accounting for gene-for-gene interaction and balancing natural selection. Observations agree well with theory.     

Selection in Early Generations of Dried Peas, Pisum sativum L. II. Significance of the Environment of Selection

In early generations peas arc frequently grown widely-spaced against wire netting under growing conditions considerably different from the commercial cultivation practice of dense stands. In 1985 and 1986, five morphologically different pea varieties were grown both widely-spaced against wire and in dense stand in plots. In the plot stands no methods to prevent the peas from lodging were used. Grain yield and yield-related traits were recorded in both environments of selection, i.e. ‘wire netting’ and ‘plot stand’. Data were analyzed with respect to the suitibility of the environment ‘wire netting’ for selection for grain yield to be realized in commercial stands of the crop. Against wire, the grain yield, number of podded lateral branches, number of podded nodes/main stem, and the profile of grain yield/node on the main stem were the most responsive characters as compared to the standard plot with a dense stand. The relative increase differed between genotypes, which was also indicated by highly significant genotype × environment interactions. Only small changes consistent over genotypes were observed for thousand grain weight (slightly lower), number of seeds/pod (slightly increased) and grain yield/pod (slightly higher). Against wire, the expression of varietal variation was higher for most characters. In addition, single plant error was lower, so that at the wire heritability values based on individual plants were larger than in the plots. The significance of the present results and the effects of competition on selection in early generations in dried peas are discussed.     

Genetic Variation for Anther Callus Inducibility in Crosses of Highly Culturable Winter Wheats

Heritability studies suggest that variation among genotypes for callus inducibility should respond to selection. The objective of this study was to determine if crosses among parents with high callus initiation frequencies would produce segregation from which genotypes with improved callus inducibility could be selected. The winter wheat (Triticum aestivum L.) cultivars‘Centurk 78’, ‘Norstar’ and ‘Norwin’ were chosen as parents, based on their high callus initiation frequencies and diverse parentage. F₂ populations from crosses between each of these parents were evaluated for callus initiation frequencies and callus vigor as determined by growth rate and healthy appearance. Heterosis was detected for callus initiation in the‘Norwin’בNorstar’ cross and for callus vigor in all crosses. Broad sense heritability estimates of 0.25 and 0.37 for callus initiation in the ‘Centurk 78’בNorstar’ and ‘Norwin’בNorstar’ crosses, respectively, suggest this trait can be improved by selection. Heritability estimates for callus vigor were less promising, ranging from 0.11 to 0.24.     

Recurrent selection progress in a population derived from an interspecific peanut cross

Summary Two cycles of recurrent selection for yield were previously conducted using a population of Arachis hypogaea L.-like tetraploid hybrid derivatives selected from among the progeny of a cross between A. hypogaea and A. cardenasii Krap. et Greg. nom. nud., a diploid species with resistance to late leafspot (Cercosporidium personatum (Burk. and Curt.) Deighton). Using the 10 highest yielding parents from each of the above cycles of recurrent selection, a study was conducted for 12 morphological traits and susceptibility to leafspot infection in a replicated test at a single location. The two parents used to initiate the interspecific hybrid population (PI 261942-3 and A. cardenasii) as well as two adapted cultivars (Florigiant and NC 7) were included as checks. The objectives of the study were to determine the amount of genetic variation remaining in the population after two cycles of recurrent selection in order to predict whether further progress from selection could be expected and determine the potential for utilizing wild species for the improvement of quantitative traits in peanut. The results indicate that significant levels of genetic variation remain in the population after two cycles of recurrent selection for all traits measured, including several components of yield and leafspot resistance. This suggests that continued progress in population improvement from further cycles of selection should be possible while enhancing the genetic diversity of cultivated peanut germplasm.Paper no. 12347 of the Journal Series of the North Carolina Agric. Res. Serv., Raleigh, NC 27695-7643. This work was partially funded by the Peanut CRSP, USAID grant number DAN-4048-G-SS-2065-00. Recommendations do not represent an official position or policy of USAID.     

不同花生品种生产力的比较

对7个花生品种在4个试点的农艺性状和经济性状进行分析,比较不同花生品种的生产力及其应用前景。结果表明：不同品种以及同一品种在不同试点其农艺和经济性状均存在明显差异,其中,单株总分枝数、单株结果枝数、单株总果数和单株饱果数较易受环境影响,而出仁率较为稳定性。泰花5号产量潜力较高,适合本区域种植。泰花2号适合在南京、如皋、盱眙等地区种植。花育23号也具有较高的产量潜力,且产量稳定性较好,适合南京、如皋、泗洪等地区种植。     

运旱号强筋抗旱丰产系列小麦品种选育研究

为育成适宜中国黄淮麦区旱地种植的优质强筋抗旱丰产小麦新品种,选育研究突出了强筋力品质改良的的高产优质育种目标和重视利用具有国外优质种质背景的品种资源。通过生态适应合理组配亲本,调节花期活性杂交,高分子量麦谷蛋白亚基分子标记检测和面筋数量及质量的品质测定辅助选择,生态适应协调特征特性选育和生态适应异地多年多点及水旱地鉴定鉴选,重视系统观察考种和综合评价优选及优系优中选优等育种策略和方法技术的应用,克服了利用国外种质杂交和冬春杂交的抗旱、耐热、抗冻及适宜熟性等特性适应性差的技术问题,育成了以‘运旱20410’、‘运旱618’为代表的运旱号系列强筋小麦品种,品质特性实现了由中强筋到稳定性强筋的创新改良,具有比‘晋麦47’增产2%~10%的高产潜力和较强的抗旱抗干热风能力。实现了抗旱丰产与强筋品质性状的有机结合。     

Genetic response to index selection for grain yield, kernel weight and per cent protein in four wheat crosses

Quantitative genetic theory was used to investigate selection differentials, expected and observed direct and correlated responses to simultaneous improvement of grain yield, kernel weight, and grain protein content in F₃ and F₄ populations of four spring wheat (Triticum aestivum L.) crosses. Selection in the F₃ generation based on the Smith-Hazel index (SH) and yield was found to be superior to the other methods studied in identifying high-yielding lines, but resulted in substantial decrease in grain protein level. Consequently, a 1.0% increase in protein from selection for protein depressed grain yield as much as 536 kg/ha below the population mean, reducing the expected yield gains per generation selection cycle by 250%. The weight-free indices (EW), particularly the index involving only yield and kernel weight (EW3) and its linear approximation (EW4), and the desired gains indices were effective in improving protein content but were less efficient in selecting top-yielding lines. Selection in the opposite direction using truncation of the lowest 10% of the population based on weight-free-index involving yield, kernel weight and protein (EW2) reduced all traits significantly compared with the mean of the unselected population indicating the effectiveness of the unweighted selection index. The observed genetic gains (Ra) from selection based on yield, the SH, EW3 and EW4 indices were slightly lower than the expected advances per cycle (R) in populations from crosses ‘Sinton’בGlenlea’ (C1), ‘Glenlea’בNB505’ (C2), and ‘A2P5’בNB320’ (C6) (Ra/R = 70 to 85%) but were higher in cross ‘NB505’בA2P5’ (C5) (Ra/R = 126 to 143%). It was concluded that weight-free and the desired gains indices can be used to improve wheat grain yield and grain protein simultaneously in F₃ generation selection, as revealed by response to selection measured in the F₄ generation.     

福建花生品种系谱及其性状演变分析

为了给花生新品种选育和引种工作提供依据,分析了福建省建国以来审定（认定、鉴定）的33个花生品种系谱及其产量等性状的演变。结果表明：福建花生育成品种共涉及45个亲本,其中22个来自福建省,24个亲本是育成品种,‘狮头企’、‘粤油92’、‘汕油523’和‘泉花10号’、‘泉花327’是福建花生品种的骨干亲本,品种的亲缘关系主要来自于广东。系统育种是福建1951-1980年主要的育种方法,1991年以来杂交育种成为花生育种的主要方法。随着花生品种的更换,产量水平不断提高,其中百果重、百仁重逐渐提高对花生产量起了重要作用。脂肪含量有随着时间而略有提高的趋势,蛋白质含量变化与之相反。植株高度逐渐降低,耐肥抗倒能力提高,适于密植。总分枝数略有降低,而结果枝数变化不大。