Патотипно разнообразие на Uromyces appendiculatus в Североизточна България

Bean rust caused by Uromyces appendiculatus (Pers.: Pers.) Unger. is one of the most devastating fungal diseases in common beans. For the plains of Bulgaria, the disease has a sporadic spread but occurs annually in The Rhodope mountains. To determine the pathotype diversity in Northeastern Bulgaria, seventeen single uredinium isolates (SUIs) were obtained from a naturally occurring pathogen population. The virulent phenotype of the isolates to the differential set referred them to 16 pathotypes of four races. The pathotypes of race 20-16 had the highest frequency of isolation (56.3%), followed by the pathotypes of race 20-18 (31.2%) and the pathotypes of races 20-0 and 20-2 (6.3%). One pathotype was referred to the Andean-specific group of the pathogen and 15 pathotypes were referred to the nonspecific group of U. appendiculatus. All pathotypes had a completely different virulent/avirulent phenotype compared to those previously described in Bulgaria. This investigation is the first report for the distribution of pathotypes of races 20-16 and 20-18 in the country. The high pathotype diversity of U. appendiculatus in Bulgaria is due to genetic recombination during the sexual process which occurs in The Rhodope mountains, or to mutations in the pathogen population as a result of breeding pressure of the new varieties grown in the country.Ръждата по фасул, причинявана от Uromyces appendiculatus (Pers.: Pers.) Unger, е едно от най-вредоносните гъбни заболявания по обикновения фасул. За равнинните части на България болестта има спорадичен характер, но се среща ежегодно в Родопите. За определяне на патотипното разнообразие на патогена в Североизточна България са изолирани 17 моносорови изолата. Вирулентният фенотип на изолатите към диференциращите сортове на ръждата по фасула отнася изолатите към 16 патотипа на четири раси. С най-голяма честота на изолиране са патотиповете на раса 20-16 (56,3%), следвани от раса 20-18 (31,2%) и раси 20-0 и 20-2 (6,3%) съответно. Един патотип е отнесен към Andean-специфичната група на патогена, а останалите 15 патотипа към неспецифичната група на U. аppendiculatus. Всички патотипове имат напълно различен вирулентен/авирулентен фенотип в сравнение с установените до момента в България. Патотиповете на раси 20-16 и 20-18 са нови за страната. Голямото патотипно разнообразие на U. appendiculatus в България се дължи на генетични рекомбинации през половия процес, който протича в Родопите или на мутации в популацията на патогена под дейстивие на селекционния натиск на новите сортове, които се отглеждат в страната

RESISTANCE IN COMMON BEAN(PHASEOLUS VULGARIS L.) TO UROMYCES APPENDICULATUS IN BULGARIA

Common bean rust, caused by Uromycesappendiculatus, is one of the most devastating diseases in common bean. Breeding for resistant cultivars is the most effective and eco-friendly method for disease control. Although there is no targeted breeding program in Bulgaria to create resistant cultivars to the pathogen, periodic screening of the virulent diversity of U. appendiculatus and sources of resistance to the identified races/pathotypes is carried out. During the last twenty years, four investigations were made to estimate virulence diversity in pathogen population. Eleven U. appendiculatus races (20-0, 20-1, 20-2, 20-3, 20-19, 29-0, 29-1, 28-1, 52-3, 20-16 and 20-18) are identified, distributed in Rhodope mountains and North Bulgaria. Chronologically each of the studies was accompanied or followed by a screening for sources of resistance to the pathogen under field conditions. Еach study found different numbers of resistant accessions depending on the virulent potential of the population used. In three of the studies, cultivars that showed resistant phenotype under field conditions were screened against a set of races, distributed in the country in the same time, under greenhouse. Bulgarian cultivar ‘Beslet’ showed resistant reaction under field and greenhouse in all investigation. The resistance of the cultivar to races 20-1 and 20-19 is governed by a single dominant gene. This cultivar can be successfully used in a breeding program for race-specific resistance. Fifty accessions with race-nonspecific resistance, expressed by low disease intensity and resistant/susceptible infection type, are identified in two investigations under field conditions

Equilibrium isotherms of red beetroots

The equilibrium moisture content of red beetroot has been studied and the corresponding sorption- desorption curves have been obtained at temperature 20°C. The strain measurement method has been used to establish the sorption curves. Analytical dependence describing the sorption and desorption curves have also been derived. Values of equilibrium moisture contents for temperatures higher than 20°C have been obtained by the Pass and Slepchenko’s method. The results are presented in graphical and table form

Laboratory convective dryer combined with microwaves

A laboratory equipment for combinations of convective and microwave drying is presented. It was applied for drying of parsnips. Lower energy consumption at microwave heating of the product at intermitted drying is confirmed in comparison to continuous convective drying with hot air. In addition, the influence of the drying process on the phenols and flavonoids contents in at continuous convective drying were investigated. The results give useful information for the organisation and the operating of the drying modes of vegetables

Resistance of foreign pea cultivars and lines (Pisum Sativum L.) to Pseudomonas

<p>The investigation was carried out during 2013-2014 at Dobrudzha Agricultural Institute, General Toshevo. Thirty six foreign pea cultivars and lines with different morphological traits were used. Two strains of P.s. pv. pisi (Bz4 and NCPPB 2585) were used for inoculation. The accessions were inoculated twice: at phenophase budding (petioles) and at grain filling (pod). One accession had immune and 20 accessions had resistant/middle resistant reaction of leaves and pods to strain NCPPB. Fourteen accessions had immune/resistant/middle resistant phenotype of leaves and pods to strain Bz4. Nine accessions had immune/resistant/middle resistant phenotype of leaves and pods to both strains of P.s.pv. pisi. These accession can be used as a donor parent in a disease resistance breeding program. </p&gt

Equilibrium isotherms of red beetroots

The equilibrium moisture content of red beetroot has been studied and the corresponding sorption- desorption curves have been obtained at temperature 20°C. The strain measurement method has been used to establish the sorption curves. Analytical dependence describing the sorption and desorption curves have also been derived. Values of equilibrium moisture contents for temperatures higher than 20°C have been obtained by the Pass and Slepchenko’s method. The results are presented in graphical and table form

Muriella australis J. Phillipson (Chlorophyta), una nueva especie para la flora de algas de Bulgaria

Muriella australis J. Phillipson (Chlorophyta), una nueva especie para la flora de algas de Bulgaria Se cita una nueva especie de alga para Bulgaria. Esta rara especie (sólo conocida su locus classicus de Australia, aislada de suelo) se ha encontrado también en los montes Rópode, en la capa aerofílica del lecho de las fuentes de la villa de Slaveyno (provincia de Smolyan). Se ha extendido la diagnosis de la especie. Se ha realizado una revisión de la especie y del género.Abstract: A new species and genus Muriella australis for the algal flora of Bulgaria аre reported in this article. This rare species (known only from locus classicus in Australia, isolated from soil) was discovered also in Rhodope Mountains, Bulgaria in aerophilic coating on the bed of the fountains in village Slaveyno (Smolyan district). The diagnosis of the species was extended and expanded. A review of the species to the genus concerned was accomplished

Sorption isotherms of parsnip

Parsnip is a root that has a number of useful nutrients. For this reason, in recent years it has been rehabilitated and is widely used in dried form in the food industry and for medicinal purposes. Knowledge of its equilibrium characteristics of the products has an important practical significance, which is expressed in the selection of a suitable drying regime, selection of optimal storage conditions, determination of the energy and the form of connection of water with the material, etc. Therefore, an experimental study was performed to determine the equilibrium moisture content of parsnip and equations describing the sorption and desorption isotherms of parsnip at a temperature of 20°C were derived. Its equilibrium moisture content at higher temperatures (20, 40 and 60°C) was determined theoretically by the method of Pass and Slepchenko. All results are summarized in analytical, graphical and tabular form