兼抗麦长管蚜和大麦黄矮病毒的小麦种质田间鉴定筛选

为鉴定筛选兼抗麦长管蚜和大麦黄矮病毒(Barley yellow dwarf virus, BYDV)的小麦种质,采用自然感蚜/感病系数法,对36个外引和远缘杂交选育的小麦种质材料进行了2年的田间鉴定,并分析了感虫性与感病性的相关关系。结果表明,2年中均兼抗麦长管蚜和BYDV的种质仅有KOKIPPCAS、KOK、Amigo-3和PI137739共4个材料,占总鉴定材料的11.11%;对二者均敏感的有98-10-35q-9、186Tm39、Tam200e12-14a、Tam200(27)7、小偃22、西农1376和小偃6号共7个材料,占19.44%。其它材料仅抗虫或仅抗病,或仅在一年中表现抗病或抗虫,如材料98-10-30和98-10-35a8抗麦长管蚜,但对BYDV敏感;材料Tam200(13)G和PIG23(2)C感蚜,但对BYDV有抑制作用。BYDV发生普遍率(发病株率)和严重度(病情指数)与有蚜株率显著相关,严重度还与感蚜指数显著相关,但感病植株的病级均值与有蚜株率无显著相关性。表明自然界长期的进化和选择使许多抗病虫基因得以保存下来,但较多抗性基因只在抗病或抗虫的某一方面表现有效,需给予更多关注。     

Resistance to Root-knot Nematodes (Meloidogyne spp.) in Vegetable Crops

Abstract

The development of root-knot nematode resistant vegetable varieties has provided an alternative control method to chemical and crop rotation. The term resistance is discussed. Work on 18 vegetables is reviewed.

Thirty tomato strains resistant to one or more Meloidogyne sp. are listed, there was a marked absence of reports on varieties resistant to M. hapla. Several workers have observed resistance in some cultivated and wild Solanum spp. The resistance could be increased by further sib and backcrossing experiments. Eggplant varieties tested for resistance to Meloidogyne spp. showed varying degrees of resistance in about 14 varieties. Further backcrossing studies between Solanum melongena and S. sysimbrifolium could provide useful results. Tests on resistance to nematodes in pepper have revealed many resistant varieties. All the pepper varieties tested were susceptible to M. hapla. The nature of resistance in sweet potato has been studied. Some varieties of Cucumis spp. have been found to be resistant to Meloidogyne spp. Since no resistance was found in C. melo, these wild species could be used in the development of a commercial muskmelon variety. Tests with 83 watermelon varieties indicated that all varieties were resistant to M. hapla. It was difficult to find resistance to Meloidogyne spp. in Cucurbita, but tests on wild species have yet to be carried out. Work on lima bean, snap bean, pea, soyabean, cowpea and broadbean has produced a limited number of resistant vegetable varieties, which are described. Since resistance patterns in plants may change under different environmental or biological conditions, it is essential to test varieties under these conditions for a long period before they are released for commercial cultivation. The advantages of using resistant vegetable varieties, as compared with other methods of pest control, are outlined.     

The floating islands of Rawa Pening

Abstract

The resistance in okra (Abelmoschus esculentus (L) Moench varieties to the leafhopper, Amrasca devastans (Dist.) is governed by nonpreference and antibiosis mechanisms. The variety A.E. 22 was less preferred for oviposition and feeding compared to the susceptible variety Pusa Sawani. The rate of multiplication of the insects on the resistant variety was low compared to the susceptible variety.     

Screening rice varieties for resistance to rice yellow mottle virus disease

Abstract

Rice yellow mottle virus (RYMV) is one of the major constraints to rice production in Kenya. The reactions of 30 varieties of rice to an isolate of RYMV were studied. The appearance and development of symptoms in the various varieties were scored on a 0–5 scale. The observed reactions ranged from highly susceptible to highly resistant. Thirty‐six per cent of the varieties showed a high level of resistance while 23.3% were highly susceptible. The intermediate reactions were 16.7% resistant, 6.6% susceptible and 16.7% moderately susceptible.     

广东省149个油茶品种（系）对炭疽病的抗性及其病原菌鉴定

为明确广东省油茶品种（系）对炭疽病的抗性及引起油茶炭疽病的病原菌种类,对广东省肇庆市、广州市和韶关市的149个油茶品种（系）进行田间抗性调查,从发病组织中分离纯化致病菌,观察菌株形态学特征,并结合3-磷酸甘油醛脱氢酶（glyceraldehyde-3-phosphate dehydrogenase,GAPDH）基因扩增序列进行分子生物学鉴定。结果显示,有93.29%的油茶品种（系）发生炭疽病,3个调查地油茶炭疽病的平均发病率为18.86%~24.25%,较抗病的油茶品种（系）占调查总数的53.02%,感病油茶品种（系）占调查总数的46.98%。其中,海南3号、长林400号和湘林89号等10个品种（系）表现为近免疫,揭阳5号、桂14号和湘林350号等16个品种（系）表现为高抗,赣5190号、湘林27号和岑软11号等53个品种（系）表现为中抗,赣兴46号、赣州S4号和赣州R10号等36个品种（系）表现为中感,岑软11-3000号、长林53号和湘林67号等34个品种（系）表现为高感,其中岑软11-19号发病率高达65.00%。共分离获得油茶炭疽病致病菌25株,结合形态学特征和基于GAPDH序列的系统发育树分析,将其中24株鉴定为果生炭疽菌Colletotrichum fructicola,1株鉴定为为暹罗炭疽菌C. siamense。筛选的油茶抗病品种（系）可作为广东省油茶良种选育材料,且该省油茶炭疽病主要由果生炭疽菌引起。     

甘薯品种对蔓割病抗性的研究

1984—1987年采用盆苗接种法鉴定890个甘薯品种(系),结果表明:属于高抗和抗病型的41个;中抗型的71个;中感型的261个;感病型和高感型的517个。不同抗性型品种用不不同菌株和不同菌量测定,或在不同气候下重复鉴定,虽会发生不同幅度的抗性变化,但都保持相对稳定的抗病性。同时,用不同抗性型的10个品种分别在盆栽苗期和田间成株期进行抗性鉴定,结果证实了两者间抗性呈极显著正相关。     

Effect of two systemic fungicides on rice blast control in a rainforest zone of Nigeria

Abstract

Two systemic fungicides, benomyl (methyl 1‐((butylamino)‐carbonyl)‐1H‐benzimidazol‐2‐yl carbamate) (Benlate 50WP, E.I. du Pont de Nemours & Co.) and tricyclazole (5‐methyl‐1,2,4‐triazole (3,4‐b) benzothiazole) (Beam 75 WP, Eli Lilly & Co.), were sprayed on Faro 29, a popular shallow swamp rice, at full tillering stage for the control of natural infection of rice blast caused by Pyricularia oryzae Cav. in the rainforest zone of eastern Nigeria. The rates evaluated for each fungicide were a split application of 150 + 150, 300, and 400ga.i./ha of each fungicide. Both fungicides suppressed foliar and neck blast development, but tricyclazole was superior to benomyl. One application of tricyclazole at 400g a.i./ha at full tillering stage of rice successfully suppressed blast development and resulted in a significantly (P = 005) higher grain yield than the untreated control plants by an average of 42.17% during the 2 years of this study. Similarly, benomyl at 400g a.i./ha produced 18.94% more rice grain than the control. A fungicide such as tricyclazole may therefore be recommended for control of blast in areas where resistant varieties are not available or where popular resistant varieties become susceptible to one or the other phases of the disease.     

棉花抗蚜性与可溶性糖含量的关系

为探讨可溶性糖含量与棉花抗蚜性的关系,在室内人工接蚜为害和田间自然蚜群两种条件下,测定不同抗蚜性棉花品种受棉蚜为害后叶片中可溶性糖含量及其对棉蚜生长发育和繁殖的影响。结果表明:未受棉蚜为害时,抗性品种中可溶性糖含量高于感性品种,棉蚜为害胁迫后,抗蚜棉花品种可溶性糖含量升高,感蚜品种的可溶性糖含量降低。棉蚜的生长发育和繁殖与棉花叶片中可溶性糖含量呈显著的相关,可溶性糖与棉蚜若蚜历期呈正相关,与内禀增长率呈负相关。本研究说明可溶性糖含量对棉花的抗蚜性有一定的影响,转基因棉可溶性糖含量低于常规棉品种可能是导致非目标害虫棉蚜猖獗的原因之一。     

Study of Resistance to Orobanche ramosa in Host (Oilseed Rape and Carrot) and Non-host (Maize) Plants

Orobanche ramosa is a parasitic Angiosperm responsible for severe yield losses in several economical crops. It is a serious threat in oilseed rape in France and Morocco and is appearing in carrot crops in Morocco. In this study, several varieties of oilseed rape and carrot were screened in order to identify resistant cultivars and to characterize the resistance mechanisms involved. All the 15 oilseed rape varieties tested were susceptible. In carrot, the varieties 'Colmar à coeur rouge' and 'Nantaise demi-longue' were susceptible, whereas 'Palaiseau' and 'Buror' were resistant. In the susceptible 'Colmar à coeur rouge' carrot no defence reactions were found and the development of the parasite inhibited carrot tap root formation. In the resistant carrot varieties, the parasite germinated, became attached to the host root but became necrotic before emergence. In 'Buror' carrot, formation of a mechanical barrier was associated with the restriction to the cortex of the parasite. In maize cv. 'Vigni', a non-host of O. ramosa, thickening of xylem vessels, cell divisions in the central cylinder and formation of an encapsulation layer were observed in association with restricted development of Orobanche haustoria.     

Field evaluation of sweet corn varieties for their potential as a trap crop for Helicoverpa zea under tropical conditions

Corn (Zea mays) is widely cultivated for human food and animal feed and also provides an ecosystem service as a trap crop for the corn earworm Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) in tomato cropping systems. To be able to use corn as a trap crop for H. zea and to prevent it turning into a source of infestation, varieties are needed that are both attractive and resistant to H. zea. The main objective of this study was to compare the attractiveness to oviposition by H. zea and the resistance to H. zea of 10 sweet corn varieties in field conditions. We found Java, Garrison, Nova and Shinerock varieties that were both attractive to H. zea with a similar or higher number of eggs laid on silks than in the susceptible corn varieties, and resistant to H. zea, with fewer larvea per ear than in susceptible corn varieties. These varieties provide favorable habitats for generalist predators, ants, spiders, minute pirate bugs and lady beetles, which may account for their “dead-end” properties. Tropical farmers now have sweet corn varieties that can serve both as cash crops and as trap crops for H. zea.     

Tenth Commonwealth Entomological Conference

Abstract

Seeds of 22 rice strains carefully selected for resistance by continuously testing under high gall midge pressure at Cuttack (Orissa) through 1979–198’ and three such strains from Raipur (Madhya Pradesh) were assembled along with susceptible standard Jaya and were simultaneously tested at both locations (Cuttack and Raipur) against the Asian rice gall midge Orseolia oryzae Wood‐Mason in wet season 1985. Eighteen entries proved resistant at both locations. While Asha, Usha and Samrudhi were resistant at Raipur and susceptible at Cuttack, Shakti IR.36, IR.50, Daya and Pratap were resistant at Cuttack and susceptible at Raipur, based on which characterization of the Cuttack (Orissa) and Raipur (Madhya Pradesh) gall midge biotypes was proposed. In gall midge biotypes testing, meticulous selection of only such entries with consistently proven resistance to gall midge at least at one location, carrying forward seed from resistant plants only each season under high gall midge pressure (with 100% seedling/hill infestation in oft repeated susceptible check) and classification of test entries at the strain's level either as resistant or as susceptible without scope for the third ‘moderate’ category to intervene, generally ignored by earlier workers, were stressed.     

Anthracnose of capsicum in Papua New Guinea; varietal reaction and associated fungi

Abstract

Twenty‐three varieties of Capsicum annuum (L.) were assessed for levels of natural anthracnose infection. Infection rates ranged from 0.0 to 17.2% with sweet bell varieties being generally more susceptible than long pungent varieties. The primary pathogen appears to be Colletotrichum capsici (Syd.) Butler & Bisby but Curvularia Iunata (Wakker) Boedjin was also frequently associated with the disease.     

水稻品种对稻褐飞虱抗性的研究

水稻品种对褐飞虱的不同生物型反应是不相同的。试验结果证实:(1)褐飞虱若虫在敏感性品种上的生存率显著地高于抗性品种。在TN_1上,无论那种生物型的生存率均很高;而栖息在Mudgo的褐飞虱若虫,其生存率以生物型2的最高,而生物型1与生物型3的均很低,栖息在ASD_7的若虫,以生物型3的生存率最高。(2)褐飞虱在敏感品种上的后代群体密度显著地比抗性品种的大。生活在敏感品种的若虫,发育进度较抗性品种的快,并且身体较重。(3)在敏感品种取食的飞虱,其分泌的蜜露量较抗性品种的多,生物型2取食Mudgo的和生物型3取食ASD_7的均分泌较多的蜜露。上述结果说明了水稻品种抗褐飞虱的机制属抗生性范畴。     

Agronomic performance of a triazine resistant foxtail millet (Setaria italica (L.) Beauv.)

The agronomic performance of a foxtail millet line resistant to atrazine, obtained through interspecific hybridization between Setaria viridis and S. italica, was compared to that of the original susceptible cultivar of S. italica. In spite of lower grain yields when both were grown in identical conditions, the use of this resistant material is justified because its yield when weeded with atrazine was similar to that of the susceptible cultivar with handweeding. There were no differences in early season growth rates between these lines at cool temperatures.     

A refined inoculation method to evaluate false smut resistance in rice

False smut, caused by Ustilaginoidea virens, is a serious disease of rice worldwide. To evaluate false smut resistance in rice, we developed a method combining the cultivation of the main culm of rice plants in the greenhouse and rapid preparation of a conidial suspension to inject into the leaf sheath. The method was used to evaluate false smut resistance in 18 varieties/lines of rice. For comparison, field trials were also carried out in 2007 and 2008. The results indicated that the greenhouse method was more reproducible than field trials: commercial varieties tested were resistant; almost all the forage varieties were highly susceptible; and blast-resistant varieties/lines were mostly resistant to false smut. Thus, this inoculation method will be useful for determining the level of false smut resistance in rice and for breeding resistant varieties.     

Involvement of phenolic compounds in the resistance of grapevine callus to downy mildew (Plasmopara viticola)

Callus tissue of different grapevines (Vitis spp.) was inoculated withPlasmopara viticola. Short, highly-branched hyphae with necrosis, and long hyphae with heavy sporulation were observed on resistant and susceptible callus respectively. Thin-layer chromatography and spectrophotometric analysis showed that resistant callus contained greater quantities of gallocatechin derivatives than susceptible callus. Regression analysis between the field disease rating of each variety and its gallocatechin derivatives content indicated 92.2% correlation. Histochemical studies showed that, after infection withP. viticola, flavonoids appeared in the superficial cell walls of the callus, to a lesser degree on susceptible callus than on resistant callus. At a late stage of infection, the superficial cells of resistant callus were suberized, which did not occur in susceptible callus. This study showed that the preformed gallocatechin derivatives, the induced flavonoids and suberized superficial cells might play a role in the resistance of grapevine callus tissue to this fungus.Abbreviations CallusI Callus ofV. riparia var. Gloire de Montpellier - CallusV Callus ofV. vinifera var. Grenache - TLC Thin Layer Chromatography - var. variety - GAD Gallic acid derivatives - GD gallocatechin derivatives - RC resistant callus - SC susceptible callus     

水稻品种抗性对白背稻虱羧酸酯酶和磷酸酶活力的影响

取食感虫品种的白背稻虱若虫体内羧酸酯酶(CarE)、酸性磷酸酶(AcpE)和碱性磷酸酶(AkpE)的活力明显高于取食抗虫品种的;取食中抗和中感品种的介于取食感虫品种和抗虫品种之间。水稻不同抗性品种对白背稻虱成虫及第二代若虫上述三种酶活力的影响也有类似倾向。     

福建省甘薯蔓割病现状与研究进展

概述了甘薯蔓割病在福建的发生流行特点,病菌与寄主的互作关系,以及选育与推广抗病品种,感病品种 种苗用药处理的防治技术,为防治由镰刀菌引起的甘薯蔓割病提供借鉴。     

A rapid technique for screening banana cultivars for resistance to Xanthomonas wilt

The banana Xanthomonas wilt disease (BXW) has threatened the livelihood of millions of farmers in East Africa. Use of resistant varieties is the most cost-effective method of managing this bacterial disease. A reliable and rapid screening method is needed to select resistant banana varieties. An in vitro screening method was developed for early evaluation of Xanthomonas wilt resistance using small tissue culture-grown plantlets. Eight cultivars of banana were screened with sixteen isolates of Xanthomonas campestris pv. musacearum using this method. There were significant differences (P < 0.0001) in susceptibility among the various banana cultivars tested, whereas no significant difference (P = 0.92) in pathogenicity was observed between the pathogen isolates. The cv. Pisang Awak (Kayinja) was found to be highly susceptible and Musa balbisiana resistant. Nakitembe was found to be moderately resistant while cvs Mpologoma, Mbwazirume, Sukali Ndiizi, FHIA-17 and FHIA-25 were susceptible. The susceptibility of these cultivars was further tested in vivo by artificial inoculation of potted plants with similar results. This study shows that an in vitro screening test can serve as a convenient, cheap and rapid screening technique to discriminate BXW-resistant from BXW-susceptible banana cultivars.