scholarly journals Sources of Resistance to Crenate Broomrape Among Species of Vicia

Plant Disease ◽  
2005 ◽  
Vol 89 (1) ◽  
pp. 23-27 ◽  
Author(s):  
J. C. Sillero ◽  
M. T. Moreno ◽  
D. Rubiales

Crenate broomrape is a parasitic weed that represents a major constraint for pulse and forage legume production in the Mediterranean and West Asia regions. Control strategies have centered around agronomic practices and the use of herbicides, although success has been marginal. Resistance breeding is hampered by scarcity of proper sources of resistance and of a reliable and practical screening procedure. A germ plasm collection of 208 accessions of vetch belonging to 42 Vicia spp. was screened for resistance to crenate broomrape under field conditions. High levels of resistance were found in several species. Resistance of selected accessions was confirmed by a low induction of broomrape seed germination in pot and in vitro experiments. This was followed by a scarce establishment of broomrape radicles in contact with host roots and a limited development of established tubercles. In addition, a hypersensitive-like necrosis occasionally was observed, but at low frequency.

2005 ◽  
Vol 45 (10) ◽  
pp. 1291 ◽  
Author(s):  
T. T. Nguyen ◽  
P. W. J. Taylor ◽  
R. J. Redden ◽  
R. Ford

Cultivated chickpea germplasm collections contain a low frequency of ascochyta blight resistant accessions. This might lead to limitations on the future progress of chickpea breeding worldwide. In an effort to identify novel sources of resistance to ascochyta blight, 56 unique accessions, comprising 8 annual wild Cicer species, were evaluated under a controlled environment that was optimal for infection with an aggressive Australian isolate of Ascochyta rabiei (Pass.) Labrousse. The majority of wild Cicer accessions were either susceptible or highly susceptible to A. rabiei 21 days after inoculation; however, 11 accessions, of which 7 were Cicer judaicum, were resistant. The most resistant accession detected in this study, ATC 46934, together with accessions ATC 46892 and ATC 46935, which were resistant in this and another study, should be targeted for use in future interspecific resistance breeding programs.


Botany ◽  
2011 ◽  
Vol 89 (12) ◽  
pp. 813-826 ◽  
Author(s):  
M. Fernández-Aparicio ◽  
J.H. Westwood ◽  
D. Rubiales

A number of plant species have adapted to parasitize other plants, and some parasitic species pose severe constraints to major crops. The role of strigolactones and other metabolites present in host root exudates as germination stimulants for weedy root parasitic weed seeds has been known for the last 40 years. Recently, the ecological and developmental roles of strigolactones have been clarified by the discovery that they are a new class of plant hormone that controls shoot branching and serve as host recognition signals for mycorrhizal fungi. Parasitic plants also recognize these chemicals and use them to coordinate their life cycle with that of their host. Here we review agronomic practices that use parasitic germination stimulant production as a target for manipulation to control parasitic weeds.


2016 ◽  
Vol 10 (1s) ◽  
pp. 39 ◽  
Author(s):  
Grazia Disciglio ◽  
Francesco Lops ◽  
Antonia Carlucci ◽  
Giuseppe Gatta ◽  
Annalisa Tarantino ◽  
...  

The root-parasitic weed <em>Phelipanche ramosa</em> (L.) Pomel represents a major problem for processing tomato crops. The control of this holoparasitic plant is difficult, and better understanding of treatment methods is needed to develop new and specific control strategies. This study investigated 12 agronomic, chemical, biological and biotechnological strategies for the control of this parasitic weed, in comparison with the untreated situation. The trial was carried out in 2014 at the Department of Agriculture, Food and the Environment of the University of Foggia (southern Italy), using processing tomato plants grown in pots filled with soil from a field that was heavily infested with <em>P. ramosa</em>. After transplantation, top dressing was performed with 70 kg ha<sup>–1</sup> nitrogen. A randomised block design with 3 replicates (pots) was adopted. During the growing cycle of the tomato, at 70, 75, 81 and 88 days after transplantation, the number of parasitic shoots (branched plants) that had emerged in each pot was determined, and the leaf chlorophyll of the plants was measured using a soil-plantanalysis- development meter. At harvesting on 8 August 2014, the major quanti-qualitative yield parameters were determined, including marketable yield, mean weight, dry matter, soluble solids, and fruit colour. The results show lower chlorophyll levels in the parasitised tomato plants, compared to healthy plants. None of the treatments provided complete control against P. ramosa. However, among the methods tested, Radicon® biostimulant (Radicon, Inc., Elk Grove Village, IL, USA), compost activated with <em>Fusarium oxysporum</em>, nitrogen and sulphur mineral fertilisers, Enzone<sup>TM</sup> soil fumigant (Elliott Chemicals Ltd., Auckland, New Zealand), and a resistant tomato genotype mitigated the virulence of the attacks of this parasite. These effects should be improved by combining some of these treatments, especially for gradual and continued reduction in the <em>seed bank</em> of the parasite in the soil. For the tomato yields across the different treatments, there were no significant differences seen; however, the yields showed an improving trend for treatments with lower presence of the <em>P. ramosa</em> weed.


2012 ◽  
Vol 10 (3) ◽  
pp. 258-260 ◽  
Author(s):  
Mohar Singh ◽  
Z. Khan ◽  
Krishna Kumar ◽  
M. Dutta ◽  
Anju Pathania ◽  
...  

Fusarium wilt caused by Fusarium oxysporum, Schlecht. emend. Snyd. & Hans. f. sp. ciceri is prevalent in most chickpea-growing countries and is a major devastating disease. Host plant resistance is the most practical method of disease management. Indigenous chickpea germplasm reveals a heterogeneous genetic make-up and the response of resistance to wilt is an unexplored potential source for disease resistance. There are 70 indigenous germplasm lines selected on the basis of their agronomic performance and diverse areas of collections in the country. Of these, four accessions had a highly resistant score of 1 and six had a score of 3 using a 1–9 rating scale, indicating their level of resistance to Fusarium wilt (race 4). Other germplasm accessions of chickpea were found to be moderately resistant to highly susceptible disease reaction. Likewise, the same set of germplasm was also screened for Meloidogyne incognita (race 1) using pot culture under controlled condition. Only one accession was found to be resistant to this pest. These resistant gene sources can be utilised effectively for race-specific chickpea wilt and root-knot resistance breeding programmes.


2018 ◽  
Vol 110 ◽  
pp. 86-95 ◽  
Author(s):  
Anna Koziorowska ◽  
Ewa Monika Waszkiewicz ◽  
Maria Romerowicz-Misielak ◽  
Kamila Zglejc-Waszak ◽  
Anita Franczak

2021 ◽  
Author(s):  
Yujian Ren ◽  
Jingxiang Li ◽  
Yuanzhe Dong ◽  
Dong Jin ◽  
Shengdun Zhao

Abstract High efficiency and good section quality are two main objectives of metal bar cropping. A suitable control method can help to achieve both goals. An investigation of the control method of low-cycle fatigue cropping (LCFC) based on the acoustic emission (AE) technique has been proposed in this study. Ring-down counts and kurtosis are used to monitor the whole process of LCFC. The results showed that kurtosis is more suitable for monitoring the LCFC process and as a critical parameter to optimize the control method than ring-down counts in the noisy factory environment.Moreover, three types of materials are studied in this experiment; by combine with the AE results, macroscopic images and microscopic images of sections, characteristics of various LCFC stages are obtained. The results also indicated reduce the area of the transient fracture zone is the key to improve the section quality. Reducing the load frequency before the unstable crack propagation stage will beneficial to realize the goals. Based on the evaluation of kurtosis, an optimized control method is presented, and two control parameters: transient time T and the critical value of the slope of kurtosis C are determined. For 16Mn, 1045 and Al 6061, the T is 5s, 10s, and 1s, respectively. For 16Mn, 1045, and Al 6061, the C is 100, 300, and 0, respectively. Two parameters, h and S, are used to evaluate the section quality and four control strategies are compared. The results indicate the optimal control methods can improve the section quality effectively. The influence trend of reducing loading frequency is investigated by further comparison. It can be seen as the frequency decreases, the efficiency of the section quality improving decreases. In order to realize the optimal results, different control strategies are adopted for different materials. Strategy 1 (high frequency is 20Hz,high frequency thought the whole process), strategy 2 (high frequency is 20Hz,low frequency is 8.33Hz), and strategy 3 (high frequency is 20Hz,low frequency is 6.67Hz) is suitable for Al 6061, 1045, and 16Mn, respectively.


Plant Disease ◽  
2021 ◽  
Author(s):  
Gondi S Arunakumar ◽  
Belaghihalli Nanjappa Gnanesh ◽  
Haniyambadi B Manojkumar ◽  
Doss S. Gandhi ◽  
Mogili Thallapally ◽  
...  

Mulberry (Morus spp.) is an important crop in the sericulture industry as the leaves constitute the primary feed for the silkworm. The availability of diverse genetic sources of resistance to root- knot nematode (RKN; Meloidogyne spp.) are very scanty and therefore, a set of 415 varied exotic and indigenous germplasm accessions were screened under glasshouse conditions. Twenty one accessions were identified as highly resistant and 48 were resistant, the highest numbers of highly resistant/resistant accessions were found in Morus alba. Further, thirty accessions based on rooting ability were evaluated for field resistance at four different locations with infested soil. Finally, eight germplasm accessions; BR-8, Karanjtoli-1, Hosur-C8, Nagalur Estate, Tippu, Calabresa, Thai Pecah and SRDC-3 were identified as potential genetic sources in RKN resistance breeding programs or as resistant rootstock for the establishment of mulberry gardens. Sixteen SSR markers analyzed among the 77 resistant and susceptible accessions, generated 55 alleles, ranging from 2 to 5 with an average of 3.43 alleles per locus. Principle coordinate analysis grouped the accessions on the basis of RKN susceptible and resistant to a greater extent. The RKN susceptible accessions exhibited higher variability as compared to resistant accessions and they were more dispersed. Analysis of molecular variance showed that maximum molecular variance (78%) within the population and 22% between populations. Results of this study indicate that SSR markers are reliable for assessing genetic variability among the RKN resistant and susceptible mulberry accessions.


2002 ◽  
Vol 21 (6) ◽  
pp. 649-656 ◽  
Author(s):  
Max Nedelmann ◽  
B. Martin Eicke ◽  
Ernst G. Lierke ◽  
Axel Heimann ◽  
Oliver Kempski ◽  
...  

Author(s):  
Gundula B. Runge ◽  
Al Ferri ◽  
Bonnie Ferri

This paper considers an anytime strategy to implement controllers that react to changing computational resources. The anytime controllers developed in this paper are suitable for cases when the time scale of switching is in the order of the task execution time, that is, on the time scale found commonly with sporadically missed deadlines. This paper extends the prior work by developing frequency-weighted anytime controllers. The selection of the weighting function is driven by the expectation of the situations that would require anytime operation. For example, if the anytime operation is due to occasional and isolated missed deadlines, then the weighting on high frequencies should be larger than that for low frequencies. Low frequency components will have a smaller change over one sample time, so failing to update these components for one sample period will have less effect than with the high frequency components. An example will be included that applies the anytime control strategy to a model of a DC motor with deadzone and saturation nonlinearities.


Sign in / Sign up

Export Citation Format

Share Document