Relative resistance of derived cultivars of soybeans to the cyst nematode, Heterodera glycimes Ichinohe

The three soybean cultivars, Custer, Pickett 71 and Forrest, which derived their resistance to race 3 of soybean cyst nematode (Heterodera glycines Ichinohe) from the variety Peking, were tested for their level of resistance. Similarly, Bedford, Nathan, D75-10710 and Bradley cultivars which are resistant to race 4 were compared against their donor parent PI 88788. Each soybean line was inoculated with eggs and larvae of known cyst-nematode cultures. Custer, Pickett 71, Forrest and Peking had equal levels of resistance to race 3 and all were equally susceptible to the culture developed on Forrest; however, Peking and Custer had fewer white females against PI 88788 culture than did those on Pickett 71 and Forrest. Among cultivars resistant to race 4, Nathan had a greater number of white females than PI 88788 against cultures developed on Essex, Bedford and Peking. In general, the derived cultivars had a greater number of white females per plant than their donor parents.     

中国大豆抗(耐)胞囊线虫病品种及其系谱分析

大豆胞囊线虫病是大豆生产上的重要病害,给大豆生产造成巨大损失.种植抗病品种是经济有效、环境友好型防治方法,国内外大豆抗胞囊线虫病育种取得了较大成绩.汇总我国自1978年以来所审定的大豆抗(耐)胞囊线虫病品种,系谱分析了其抗病基因来源,指出了我国抗病品种遗传基础狭窄,抗病品种抗性单一的问题,提出了利用新的抗源或新型抗病基因是拓宽抗病品种遗传基础的重要途径,并就未来研究从3个方面进行了探讨,以期能够对我国抗病育种提供参考.     

Seed characteristics and nutrient composition of selected beans (Phaseolus vulgaris L.) with different ozone tolerance

Ozone sensitivity, nutritional quality, seed characteristics, and growth habit of beans (Phaseolus vulgaris L.) were evaluated in two seperate experiments. In the first experiment the data showed a significant variation among 34 bean accessions for ozone sensitivity following acute exposure of 18-day-old plants to 0.6 µl/l O₃ for 2 hours under environmentally controlled greenhouse conditions. PI-163579, PI-169735, PI-171790, PI-176684, PI-201374, PI-310711, PI-345576, PI-370569, PI-379435, and PI-414831 were identified as tolerant to acute ozone exposures. Protein, oil, starch, sugar, and ash contents in the seed of selected germplasm were determined and no correlation was found between these components and ozone sensitivity. Seed size and growth habit varied considerably among the 34 accessions but were not correlated to ozone sensitivity. In a second experiment, ten accessions, selected from the tolerant ones identified in the first experiment, were subjected to chronic ozone exposure in open-top chambers at 0.04 and 0.08 µl/l concentrations for 7 hours/day 44 days after transplanting. Based on foliar injury and yield reductions, only PI-370569 and PI-414831 were tolerant to prolonged ozone exposure (0.08 µl/l). A significant positive correlation (r=0.83) existed between foliar injury rating from chronic treatments involving 0.04 and 0.08 µl O₃/l and acute exposure (0.6 µl O₃/1/2 hours). The data indicated that acute ozone exposure can be used to initially screen a large number of bean accessions, however, this is an imperfect indicator of ozone sensitivity with chronic exposure.Agricultural Research Station Journal Article Series, No. 191. The use of any trade name varieties and/or vendors does not imply the exclusion of other products or vendors that may also suitable.     

Differential ozone susceptibility of Centennial Russet and White Rose potato as demonstrated by fumigation and antioxidant treatments

Because quantitative field estimates of potato (Solarium tuberosum L.) yield losses attributable to ozone (O₃) air pollution damage in California need to be assessed, the antioxidant compound N-[-2-(2-oxo-l-imidazolidiny l)ethyl]-N′-phenylurea (EDU or DPX-4891) was evaluated for suitability in estimating these yield losses and in differentiating O₃-susceptible from O₃-resistant cultivars. Differential susceptibility of two cultivars, ‘Centennial Russet’ (O₃sensitive) and ‘White Rose’ (O₃-resistant), to O₃ was confirmed in greenhouse experiments. Five weekly 5-hour treatments with 25 parts per hundred million O₃ reduced tuber yield of Centennial Russet by 32% but did not reduce the yield of White Rose. In the absence of O₃ under greenhouse conditions, EDU had no observable effect on shoot dry weight, tuber number, or tuber yield of either cultivar, suggesting that EDU does not materially affect plant growth in the absence of O₃ at the treatment levels used and under the conditions herein. In field experiments conducted at the University of California at Riverside (UCR) and in commercial fields of Kern County (KC), untreated Centennial Russet and White Rose plants produced total tuber yields of 174 and 512 q/ha, respectively at UCR and 268 and 498 q/ha, respectively, at KC. At UCR, EDU applied at the highest rate—17.8 kg/ha—increased marketable and total tuber yields of Centennial Russet by 208 and 188 q/ha, respectively, and increased specific gravity by 0.013. White Rose was not affected by EDU. Averaged over four KC experiments, EDU application at 8.9 kg/ha increased Centennial Russet marketable and total tuber yields by 40 (from 214) and 45 (from 268) q/ha, respectively, whereas White Rose was not affected and averaged 398 (marketable) and 491 (total) q/ha.     

广西育成大豆品种亲本分析

为提高优异品种选育效率，本研究对广西已育成的39个大豆品种系谱进行追溯，分析其亲本组配方式、地理来源及细胞核（质）遗传贡献，结果表明，育成的39个大豆品种（春大豆28个，夏大豆11个）来源于40个细胞核祖先亲本，17个细胞质祖先亲本；来源于广西本地、外省和国外祖先亲本的核（质）遗传贡献率分别为39.42 %（58.98%）、45.75 %（38.46%）和14.83 %（2.56%）；核祖先亲本主要来源于广西本地及生态条件相近的我国南方、巴西和美国。春大豆育成品种细胞质祖先亲本主要来源于广西、湖北和北京，夏大豆育成品种细胞质祖先亲本主要来源于广西、湖北和上海；2006年以来，96%的大豆育成品种是以育成品种和国外引种作为亲本组配而成；归纳出靖西早黄豆等8个核心春大豆祖先亲本，平果豆等5个夏大豆核心祖先亲本。广西大豆育成品种核遗传基础较为丰富，但还需加强新种质研究利用，以扩大品种的核质基础。        

从获奖品种系谱分析大豆杂交亲本选配方法

通过对获奖大豆品种黑河3号、合丰25号和绥农14号的系谱分析,归纳出获奖大豆品种的直接亲本和祖先亲本,总结了这些亲本的来源和类型,梳理出获奖品种培育过程中亲本选择和组配上的共同特点,分析了获奖品种在亲本选配上的方法,直接亲本对获奖品种的遗传贡献率。获奖品种比普通品种含有较多的祖先亲本血缘,遗传基础比较丰富,新育成的获奖品种比早期育成品种更加拓宽了遗传基础。对大豆杂交亲本选配和提高育种工作效率有重要的预测指导作用。     

Evaluation of soybean for resistance to soybean rust in Vietnam

Soybean rust, caused by Phakopsora pachyrhizi Sydow, is a severe foliar disease of soybean [Glycine max (L.) Merr.] that occurs throughout most soybean producing regions of the world. The objective of this research was to evaluate selected soybean genotypes for resistance to soybean rust in Vietnam. Five field experiments in Vietnam were completed from 2006 to 2009. The area-under-the-disease-progress-curve (AUDPC) was calculated for each soybean genotype based on four disease assessments taken during the reproductive growth stages. AUDPC units among soybean genotypes in each experiment differed (P < 0.05). Over the five experiments, the resistant check DT 2000 was most often the genotype with the lowest AUDPC units while the sources of rust resistance (Rpp1-5) did not always have low AUDPC units in each experiment, although PI 230970 (Rpp2) appeared to be more stable. A few genotypes with non-characterized genes for resistance, such as PI 398998, PI 437323, and PI 549017, had the lowest AUDPC units in at least one of the experiments. These genetic resources may be useful for host plant resistance studies and breeding soybeans for rust resistance in Vietnam and other locations like Brazil and the United States that have more recently been inundated with soybean rust. A significant (P < 0.001) experiment × genotype interaction was found when the AUDPC data of 14 soybean genotypes tested in Experiments 1, 2, and 3 were combined and analyzed. This result indicates the potential importance of changing fungal races and/or biotypes that occur in the rust population.     

Observations on the occurrence and inheritance in wheat of resistance to the grain aphid Sitobion avenae

Glasshouse screening tests with the aphid, Sitobion avenae, demonstrated resistance or extreme susceptibility in a minority of winter wheat cultivars. Assessments of some, but not all, resistant cultivars were apparently affected by the conditions of the test, and field observations confirmed some, but not all, of the glasshouse results. Rapier and Galahad were the most resistant of the cultivars currently available to British wheat growers. F₄ lines of spring wheat from crosses of wheat stocks resistant to S. avenae were screened by two methods and on average were resistant. Crosses differed in the amount of variability available for further selection, and wide-ranging segregation among the lines indicated that resistance genes differed among the parent stocks.     

Inheritance of the resistance toGlobodera rostochiensis pathotype Ro2 in potato

Nine advanced tetraploid potato clones withS. tuberosum ssp.tuberosum, S. tuberosum ssp.andigena, andS. vernei background were found to be highly resistant toGlobodera rostochiensis pathotype Ro2. In order to characterize the inheritance of the resistance to Ro2 and determine the genotype of these Ro2-resistant clones, a series of testcrosses to susceptibleS. tuberosum cultivars, as well as crosses between the resistant clones, were made. A total of 1081 seedlings corresponding to 18 families were grown, inoculated with 3000G. rostochiensis juveniles (J2), and evaluated by the root-ball method. To determine which genetic model best fit the data, goodness-of-fit-tests were performed. The analysis assumed tetrasomic inheritance under the hypothesis that resistance is due to one locus with complete dominance. From the analysis of the data it is concluded that there is no consistent evidence against the hypothesis that a single dominant gene is associated with the resistance to Ro2 and that the Ro2-resistant clones are simplex. In general, the number of cysts observed on the root balls was low compared with the results of other studies, the results of the different inoculations were variable, and there was an excess of resistant plants. Possible explanations for these observations are discussed.     

Genetic analysis for resistance to the green leafhopper, Nephotettix virescens (Distant), in some cultivars of rice, Oryza sativa L.

The genetics of resistance to green leafhopper Nephotettix virescens (Distant) was studied in 17 cultivars of rice (Oryza sativa L.). Seedlings at the one-leaf stage were infested with second- and third-instar nymphs of green leafhopper. Reactions to seedling injury were recorded 7–8 days after infestation. The reactions of F₁, F₂, and F₃ populations from the crosses of resistant varieties with susceptible parent TN1 revealed that resistance of Tilakkachray, Kalimekri 77-5, and Tilockkachari was governed by two dominant genes and resistance of IR42 was conveyed by a single recessive gene. Single dominant genes govern resistance in the remaining 13 cultivars. Allele tests revealed that a single dominant gene of Segon Perak and one of the two genes of Kalimekri 77-5 are allelic to Glh 1. The single dominant gene of Ernest, Bignou and ARC614 and one of the two genes of each of Tilakkachray, Kalimekri 77-5, and Tilockkachari are allelic to Glh 2. A single dominant gene, which is allelic to Glh 3, conditions resistance in Arai and IR30. The single recessive gene which conveys resistance in IR42 appears to be allelic to glh 4. The allelic relationships of one of the two genes of Tilakkachray and Tilockkachari and single dominant genes of Fulkari 653, Chao Pho Kha, Amoule Borome, Kabero, Aus Murali, IR28 and IR34, with each other and with Glh 5 are not known.     

The Relationship Between Active Oxygen Metabolism and Resistance to Late Blight in Potato

The relationship between active oxygen metabolism and resistance to late blight (Phytophthora infestans) in potato (Solanum tuberosum L.) was studied for 72 h post-inoculation by comparing three resistant cultivars (low disease index) with three susceptible ones (high disease index). Activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), and the content of ascorbic acid (ASA), were higher in the resistant cultivars than in the susceptible ones. The production rate of the superoxide anion radical (O₂^?) was lower in the resistant cultivars than in the susceptible ones. These changes, which were associated with the potato plant’s response to infection with P. infestans, provide some insight into the physiological basis of resistance and may also provide a screening tool for resistance to late blight.     

中国大豆胞囊线虫抗源筛选及抗病育种研究进展

大豆胞囊线虫病是大豆生产上，危害最大且发生最普遍的病害，对大豆产量影响极大。应用抗病品种是防治大豆胞囊线虫病最经济有效的措施，介绍了我国大豆胞囊线虫抗源筛选及抗病育种的研究进展。     

Foliar reaction toPhytophthora infestans in inoculated potato field trials in Michigan

Late blight, caused byPhytophthora infestans, is the most important disease of potato worldwide and foliar resistance is an important component of managing late blight in the field. The objective of this research was to identify germplasm for use in breeding cultivars with foliar resistance toP. infestans. More than 500 clones were tested from 1997 to 2002 in inoculated (US8 genotype) field experiments conducted at the Michigan State University Muck Soils Research Farm in Bath, Michigan. All of the current commercial cultivars tested were classified as susceptible toP. infestans. The most resistant clones were A90586-11, AWN86514-2, B0718-3, Jacqueline Lee (MSG274-3), MSI152-A, MSJ307-2, MSJ317-1, MSJ453-4Y, MSJ456-2, MSJ456-4, MSJ461-1, MSK101-2, MSK128-1, NY121, LBR8, LBR9, Tollocan, and Torridon. Some of these resistant selections were from crosses with B0718-3, Jacqueline Lee, and Tollocan suggesting that the resistance toP. infestans was transmissible. These resistant clones will provide the opportunity to breed late-blight-resistant cultivars from a diverse pool of cultivated germplasm. Consistent foliar reaction toP. infestans over years suggested that the Michigan State University Muck Soils Research Farm is a valuable location for North American breeders to assess the reaction of potato germplasm to the US8 genotype of late blight.     

Resistance of Oryza spp. to thrips, Stenchaetothrips biformis (Bagnall) (Thysanoptera: Thripidae)

A method to evaluate rice cultivars for resistance to Stenchaetothrips biformis (Bagnall) in the greenhouse was developed. Eleven traditional cultivars of Oryza sativa and 12 wild rices were selected for resistance. Studies on the mechanisms of resistance indicated that resistant cultivars were non-preferred for feeding and oviposition. Larval survival was lower and adult life shorter on resistant compared with susceptible cultivars. Resistant cultivars had an adverse effect on fecundity and oviposition rate which resulted in a low population growth. Plant injury on susceptible cultivars reduced plant weight and height.     

东北地区大豆品种血缘组成分析

用系谱分析法研究了东北地区168个杂交育成大豆品种与其祖先品种间的亲缘系数,估计了各祖先品种对辽,吉、黑三省大豆基因库的相对遗传贡献。结果表明,我国东北地区大豆育成品种的遗传基础较窄。满仓金,紫花4号,丰地黄,元宝金,荆山朴,铁荚四粒黄,克山四粒黄,金元1号,十胜长叶和黄宝珠10个祖先品种对东北大豆杂交育成品种遗传基础的总贡献为57.7％。因满仓金,元宝金是金元×黄宝珠的后代,而荆山朴是由满仓金系选而来,因此,金元和黄宝珠约贡献了东北大豆育成品种约28.7％的遗传物质。三省比较,黑龙江省杂交育成大豆品种的遗传基础最窄,辽宁次之。为了保证持续稳定的育种进展,有必要加强对国内外大豆种质资源利用的研究。扩大种质资源的利用范围,使大豆品种的遗传基础多样化。     

Relationship of foliar ozone injury to maturity classification and yield of potatoes

Fifty-nine potato cultivars and selections were planted in replicated plots at two Ohio locations each in 1975 and 1976. Evaluations of ozone “speckle leaf” injury were made during August and yields were recorded in October. A broad range in resistance to ozone injury was noted at both locations with later-maturing entries generally being more resistant. Entries severely injured by ozone had a reduced yield. The relative resistance of most entries was constant in all tests.     

Glycoalkaloid levels in potato tubers and leaves after intermittent plant exposure to ozone

Irish potato vines of ‘Norland’ and ‘Kennebec’ cultivars were exposed to 387 μ/m³ ozone for 3 hr once every wk throughout their growth. Tubers of ‘Norland’ and ‘Kennebec’ were harvested at 120 and 140 days, respectively, from exposed and non-exposed plants. The experiment was conducted in 1977 and again in 1978. Ozone induced severe foliar injury to ‘Norland’ and slight injury to leaves of ‘Kennebec’ Tubers from ozone treated plants displayed a significant reduction (0.35 mg TTGA/100 g fresh weight tuber tissue) in tuber total glycoalkaloids (TTGA) when expressed on a fresh weight basis. However, since differences were not detected for TTGA on a dry-weight basis, the fresh-weight TTGA differences may only reflect variations in moisture content. In a separate experiment, both ‘Norland’ and ‘Kennebec’ were exposed to 488 μg/m³ ozone for 3 hr when the plants were 18 days old. When leaves were harvested three days later, no significant differences were detected between leaf total glycoalkaloid (LTGA) levels of treated and nontreated plants.     

Evaluation of various potato cultivars for resistance to wireworms (Coleoptera: Elateridae)

Fifty potato cultivars, 11 early-maturing, 11 mid-maturing and 28 late-maturing cultivars, were evaluated in the field for resistance to wireworms, using the equation injury rate (%) = (No. of damaged tubers/No. of total tubers) × 100. In preliminary field tests, four wireworm species were found in the experimental site:Selatosomus puncticollis (Motschulsky),Melanotus legatus Gandéze, Agrypnus argillaceus (Solsky), andA. binodulus coreanus Kishii. Larvae ofS. puncticollis were dominant (over 95% occurrence). Significant differences for resistance were observed among the 50 cultivars. Of 11 early-maturing cultivars, high levels of resistance to wireworms were obtained from cvs Anco and Irish Cobbler. Among the 11 mid-maturing cultivars, the American cultivar Alamo and the Japanese cultivar Shinyuseo exhibited high resistance to wireworms. Of 28 late-maturing cultivars, cvs Whitu, Sieglinde, Spunta, and Some Miore were very resistant to wireworms, whereas high levels of resistance were observed in the cvs Cardinal, Norin No. 2, Ojiro and Rosa. These resistant cultivars should be useful in future breeding programs.     

Reniform nematode resistance in potato clones

SeveralSolatium tuberosum clones were tested for resistance to the reniform nematode,Rotylenchulus reniformis. Commercial cultivars La Rouge and possibly Red La Soda had high levels of resistance to the reniform nematode.R. reniformis resistance was found to exist independently of the H₁, H₂, or H₃ genes for resistance to races of potato cyst nematodes,Globodera rostochiensis andG. pallida. In addition to reniform nematode resistance, B7642-2, B7154-8 and B7680-6 contained the H₁ gene and breeding linePI 377741 contains the H₁ and H₂ gene for potato cyst nematode resistance. Over a three month period reniform nematode counts were significantly lower in pots where resistant varieties were grown.     

大豆抗疫霉病菌的生理生化机制

从大豆膜质过氧化水平和保护酶体系的变化,分析了不同类型大豆品种在接种大豆疫霉根腐病菌条件下生理生化反应,以探索抗病品种的生理生化机制.研究结果证实,苯丙氨酸酶是诱导大豆产生全株抗性的重要酶,在接种疫霉病菌后,抗病品种苯丙氨酸酶活性迅速增强,诱导植株产生抗性.＃