小麦、蚕豆和油菜对向日葵列当种子萌发的影响

通过盆栽试验和水培试验的方法在不同地区分别种植小麦、蚕豆和油菜3种作物,研究这3种作物的甲醇浸提液以及根系分泌物对向日葵列当种子萌发的影响。结果显示,小麦和蚕豆植株的根部甲醇浸提液以及根系分泌物对向日葵列当种子的萌发有较强的刺激作用,其中小麦甲醇浸提液处理的向日葵列当种子萌发率最高(41.5%)。蚕豆植株的甲醇浸提液和根系分泌物也对向日葵列当种子萌发有较强的影响,其中蚕豆根系分泌物处理向日葵列当种子的萌发率高达41.1%。综合得出,小麦和蚕豆的根部可能含有刺激向日葵列当发芽的物质,具有作为向日葵列当诱捕作物的可能性。     

多功能列当生防镰刀菌的筛选及种类鉴定

从河北省张家口地区种植的烟草上采集的感病弯管列当植株,从中分离得到20株镰刀菌,采用孢子悬浮液浸根和灌根法对小麦、玉米、棉花、向日葵、番茄、烟草、辣椒、茄子、西瓜、甜瓜等作物和蔬菜进行了安全性检测,筛选出对主栽作物和蔬菜安全且具有促生作用的4个菌株。其中菌株Br-2对烟草、辣椒、西瓜有显著促生作用,且对弯管列当的防治效果最好:施用菌株Br-2后烟草、辣椒、西瓜增高分别为123.53%、62.16%、28.95%;其发酵上清液对弯管列当种子萌芽抑制率为71.79%;小区试验中对弯管列当的寄生率防效为50%,寄生度防效为79.38%;田间试验中对弯管列当的寄生率防效为58.27%,寄生度防效为75.70%。形态学和分子生物学鉴定结果表明菌株Br-2为尖孢镰刀菌。     

Genetics of Resistance in Vicia sativa L. to Orobanche crenata Forsk.

The genetics of resistance of common vetch (Vicia sativa L.) to broomrape (Orobanche crenata Forsk.) was studied for two years by using the P₁, P₂, F₁, BC¹, BC₂, F₂ F₃, and F₄ generations obtained from crosses between resistant and susceptible lines. Resistant lines were selected by screening a world collection m a naturally infested plot. Resistance was tested both under field and greenhouse conditions. The best index to measure resistance was the number of emerged broomrapes per host plant. The results fit the additive-dominance model. The main component of the variation was additivity; dominance and interaction effects seemed to depend on the environment. When dominance is expressed, a low number is dominant over a high number of broomrapes per host plant.     

Screening for resistance to broomrape (Orobanche cernua) in cultivated sunflower

Racial evolution of sunflower broomrape (Orobanche cernua) has been very rapid in Spain during recent years, in which resistance has been overcome several times and there has been an important increase in areas infested with this parasitic angiosperm. In order to find resistance to a highly virulent population of sunflower broomrape that could be used directly in breeding programmes, three different sets of cultivated plant material composed of 429 entries were tested by artificial inoculation. All evaluated inbred lines from Moden, Canada, were fully susceptible. Out of the 240 P.I. accessions tested, only 10 segregated for resistance to broomrape, the rest being susceptible. From the 160 USDA breeding lines evaluated, 5% were resistant and 19% segregated for resistance to O. cernua. These lines traced back mainly to crosses of RHA 274 and RHA 801 with Russian, Turkish and Romanian hybrids. The origin of P.I. accessions that segregated for resistance were primarily derived from the former USSR and from Romania.     

Search for Resistance to Crenate Broomrape (<Emphasis Type="Italic">Orobanche crenata</Emphasis> Forsk.) in Pea Germplasm

Orobanche crenata Forsk. is a major constraint for pea production in Mediterranean and East Asian countries. To solve the problem of the lack of resistance in pea cultivars, a screening for resistance was performed under field conditions in a germplasm collection of 575 accessions of Pisum sativum L. No complete resistance was found but varying levels of resistance were identified and confirmed in further field seasons and in pots experiments in the greenhouse. Resistance was quantitative resulting in a reduction in the number of emerged broomrapes per pea plant. Broomrape infection and expression of resistance proved to be highly influenced by environmental conditions. Resistance is the consequence of the combination of several resistance mechanisms preventing or hampering establishment of broomrape and/or development of established tubercles. Resistance identified could suffice to prevent broomrape damage in normal years, but might need to be implemented with other control measures in very conducive years. Resistant accessions have been crossed with pea cultivars and submitted to a breeding programme in which accumulation of levels of resistance to broomrape is a priority.     

Parasitic plant infection is partially controlled through symbiotic pathways

Legumes are unique in interacting with Rhizobium , arbuscular mycorrhizal (AM) fungi, and parasitic plants. To dissect common parts of these three plant–organism interactions, infection by Orobanche crenata was studied in mutants with altered symbiotic phenotypes of Medicago truncatula and Pisum sativum . Orobanche crenata inoculation of mutant lines carrying defective mutation in the genes dmi2 / sym19 and dmi3 resulted in an increase in O. crenata establishment. Similarly, inoculation of mutants carrying mutation in the gene sunn / sym29 that controls the autoregulation mechanism of the symbiosis, also lead to a significant increase in haustoria formation. Altogether, our results suggest that parasitic plant infection is partly controlled by both the conserved symbiotic pathway that mediates symbiont recognition and establishment and the autoregulation mechanism that regulates the extent of colonisation by Rhizobium and AM fungi.     

48%仲丁灵乳油防除向日葵列当效果研究

48%仲丁灵乳油土壤处理防除向日葵列当试验结果表明,药后60 d 48%仲丁灵乳油3 000、3 375、3 750 mL/hm2的株防效分别达到70.2%、75.1%、83.2%;鲜重防效分别达到79.8%、82.5%、85.8%,经方差分析防效显著;分别增产620.00、680.00、1 080.00 kg/hm2,效果明显,且对向日葵安全;而4125mL/hm2虽然株防效、鲜重防效显著,分别达到94.4%和93.7%,但对向日葵产生药害。因此,建议生产上使用剂量3750mL/hm2。     

Direct infection of potato tubers by the root parasite Orobanche aegyptiaca

Parasitic plants of the Orobanchaceae are known as obligate root parasites that develop haustoria that connect to roots of various host plants. This article describes, for the first time, a case where the root parasite successfully connected to potato tubers, i.e. to the swollen portion of an underground stem rather than to a root. The rhizosphere of Orobanche aegyptiaca and of its host Solanum tuberosum (potato) was carefully examined. In anatomical studies, the adventitious roots were directly connected to potato tubers. Numerous secondary haustoria, which developed along the adventitious roots in close vicinity to the potato tuber, penetrated the tuber epidermis and the perimedullary tuber parenchyma and developed xylem strands that are presumably connected to the minor xylem strands within the tuber cortex. These findings indicate that parasites of the Orobanchaceae that normally attack host roots may also parasitise underground stem tubers.     

Phelipanche aegyptiaca management in tomato

Phelipanche and Orobanche species (broomrapes) are root holoparasitic plants that cause severe damage to economically important crops. Phelipanche and Orobanche spp. are widespread in Mediterranean areas, in Asia and in Southern and Eastern Europe, attacking dicotyledonous crops and depending entirely on their hosts for all nutritional requirements. Phelipanche aegyptiaca , Phelipanche ramosa and Orobanche cernua are extremely troublesome weeds on tomatoes. These noxious parasites exert their greatest damage prior to their shoot emergence and flowering; therefore, the majority of field loss may occur before diagnosis of infection. This review summarises the four main control measures for the weedy root parasites Phelipanche and Orobanche in tomato, namely chemical and biological control, resistant varieties and sanitation. Some of these methods are commercially widely used by farmers in Israel (chemical control), some are in the final stages of development towards commercialisation (resistant varieties and sanitation), and some still require further development and improvement before commercial implementation (biological control). The review presents an up-to-date summary of the available knowledge on their use for broomrape management in processing tomatoes.