The effect of relative humidity and temperature on survival and growth of Botrytis cinerea and Sclerotinia sclerotiorum

1968 ◽  
Vol 46 (12) ◽  
pp. 1477-1481 ◽  
Author(s):  
L. Van Den Berg ◽  
C. P. Lentz

Tests with mycelium and conidia of five strains of Botrytis cinerea and mycelium of three strains of Sclerotinia sclerotiorum have shown that survival and growth of these organisms depended on relative humidity, temperature, and type and strain of organism. Survival of mycelium of both organisms in the absence of nutrients, for example, varied from 12 months at 95–100% relative humidity and 0 °C to less than 1 month at below 95% relative humidity and 20 °C, depending on strain. When nutrients were present growth occurred at solution equilibrium relative humidities over 93%; at equilibrium relative humidities below 93% no growth occurred and mycelium survived only up to 1 month. Growth rates of all strains of both organisms were similar between −0.8 and 35 °C with maximum rates at about 20 °C. Results also showed that mycelium and conidia of B. cinerea survive under the conditions at which vegetables are usually stored but that mycelium of S. sclerotiorum in most instances does not.

1969 ◽  
Vol 47 (6) ◽  
pp. 1007-1010 ◽  
Author(s):  
L. Van Den Berg ◽  
S. M. Yang

B. cinerea and S. sclerotiorum growing in a nutrient medium on the surface of carrots at 20 °C produced significantly more extracellular pectolytic enzymes when the carrots were exposed to 94–96% relative humidity than when exposed to 98–100% relative humidity. Tests in which these organisms were grown in a nutrient solution containing pectic substances showed that they produced pectolytic enzymes in significant quantities only when readily metabolizable sources of energy (e.g. ethanol, carbohydrates) were not available. These results suggest that the low relative humidity increased enzyme production by concentrating nutrients on the carrot surface to the point where they inhibited growth of the organisms and stimulated enzyme production. Tests also showed that pectolytic enzyme activity on the surface of unwashed carrots stored 9 months at 0–1 °C was substantially higher at 90–95% relative humidity than at 98–100% relative humidity. The results indicated that reduced decay at 98–100% relative humidity was largely due to lower pectolytic enzyme production.


2020 ◽  
pp. 16-19
Author(s):  
Е.В. Янченко

Цель исследований – дать оценку сохраняемости и болезнеустойчивости современных сортов и гибридов моркови столовой и определить корреляционные зависимости влияния биохимических показателей качества на сохраняемость и степень поражения моркови столовой различными видами болезней в процессе хранения. Исследования проводились в 2011–2016 годах во ВНИИО – филиале ФГБНУ ФНЦО по общепринятым методикам. В биохимической лаборатории отдела земледелия и агрохимии содержание сухого вещества определяли высушиванием до абсолютно сухого веса, общего сахара – по Бертрану, аскорбиновой кислоты – по Мурри, нитраты – ионоселективным методом. При характеристике моркови столовой важнейший показатель, определяющий его качество – количество сухого вещества и сахаров. В процессе хранения были выявлены следующие болезни моркови: серая гниль (Botrytis cinerea Pers. ex Fr.), белая гниль (Sclerotinia sclerotiorum (Lib.)), белая парша (Rhizoctonia carotae Rad.), альтернариоз (Alternaria radicina M., Dr. et E.). В большей степени сортообразцы моркови столовой поражались серой гнилью. Лучшими по сохраняемости сортообразцами были Корсар (94,6%), F1Берлин (94,5%), Берликум Роял (94,1%) и F1 Звезда (94%). Сохраняемость у зарубежных сортов и гибридов моркови столовой была немного выше, чем у отечественных (на 0,4%) как за счет меньшей величины убыли массы (6,3% против 6,4%), так и потерь от болезней (1,6% против 1,9%). Сохраняемость корнеплодов моркови находится в прямой корреляционной зависимости от содержания сухого вещества (r=+0,41), каротиноидов (r=+0,39), моносахаров (r­=+0,30) и суммы сахаров (r=+0,27). Проявление серой гнили находится в обратной корреляционной связи с содержанием сухого вещества и каротиноидов (r=-0,37 и r=-0,35 соответственно), белой парши – в прямой корреляции с содержанием сухого вещества , моносахаров и дисахаров (r= +0,21; r= +0,39; r= -0,41 соответственно), белой гнили в обратной корреляционной связи с содержанием сухого вещества, моносахаров и дисахаров. The purpose of the research is to assess the persistence and disease resistance of modern varieties and hybrids of carrots and to determine the correlation between the influence of biochemical quality indicators on the persistence and degree of damage to carrots by various types of diseases during storage. The research was conducted in 2011–2016 at ARRIVG – branch of FSBSI FSVC, according to generally accepted methods. In the biochemical laboratory of the Department of Agriculture and Agrochemistry, the dry matter content was determined by drying to absolutely dry weight, total sugar – by Bertran, ascorbic acid – by Murri, nitrates – by the ion-selective method. When describing carrots, the most important indicator that determines its quality is the amount of dry matter and sugars. During storage, the following diseases of carrots were detected: gray rot (Botrytis cinerea Pers. ex Fr.), white rot (Sclerotinia sclerotiorum (Lib.), white scab (Rhizoctonia carotae Rad.), alternariasis (Alternaria radicina M., Dr. et E.). To a greater extent, varieties of table carrots were affected by gray rot. The best preserved varieties were Corsar (94.6%), F1 Berlin (94.5%), Berlicum Royal (94.1%) and F1 Zvezda (94%). The persistence of foreign varieties and hybrids of table carrots was slightly higher than that of domestic ones by 0.4%. both due to a smaller amount of weight loss (6.3% vs. 6.4%) and losses from diseases (1.6% vs. 1.9%). The persistence of carrot root crops is directly correlated with the content of dry matter (r=+0.41), carotenoids (r=+0.39), monosaccharides (r=+0.30) and the amount of sugars (r=+0.27). The manifestation of gray rot is in inverse correlation with the content of dry matter and carotenoids (r=-0.37 and r=-0.35, respectively), white scab is in direct correlation with the content of dry matter (r= +0.21; r= +0.39; r= –0.41, respectively), white rot is in inverse correlation with the content of dry matter, monosaccharides and disaccharides.


1981 ◽  
Vol 11 (3) ◽  
pp. 689-695 ◽  
Author(s):  
Craig G. Lorimer

Mortality and growth rates of trees in various crown classes and size classes were analyzed from 40-year permanent plot records of slope and ravine forest dominated by chestnut oak (Quercusprinus L.) and northern red oak (Quercusrubra L.). Average 5-year mortality rates for suppressed trees ≥2.5 cm dbh of chestnut oak and red oak in the slope forest were 26 and 45%, respectively. None of the suppressed red oaks survived the 40-year period, compared with 14% of the chestnut oaks and 33% of the red maples (Acerrubrum L.). Mortality of oak trees in the intermediate crown class was less than half that of suppressed trees, but still much higher than that of maples and birches on the tracts. Survival was reasonably high for oaks as long as the top of the crown was receiving direct sunlight, but the expected 40-year survival rate of red oaks in such a position is only 20%, with an average growth rate of 1.0 mm in diameter per year. Curves and equations expressing average mortality and growth rates at various levels of competition are presented for each species.


2001 ◽  
Vol 31 (6) ◽  
pp. 1038-1045 ◽  
Author(s):  
Jessica J Roberts ◽  
Janusz J Zwiazek

The study examined the effects of different relative humidity conditions at germination, early growth, and following cold storage on morphological and physiological characteristics of white spruce (Picea glauca (Moench) Voss) seedlings. Seedlings that were grown for 18 weeks following seed germination at the lower, 30% RH (RHinitial) treatments were shorter and had smaller stem diameters, shorter needles with more epicuticular wax, and a greater density of needles per centimetre stem, compared with the 80% RHinitial seedlings. After 18 weeks of growth under 30, 50, and 80% RH, the seedlings were hardened off, stored for 8 weeks at 3°C and planted in pots in growth chambers under 42 and 74% relative humidity (RHsubsequent). Under 74% RHsubsequent conditions, the lower RHinitial seedlings flushed sooner and had higher growth rates compared with the higher RHinitial seedlings. When the higher RHinitial seedlings were placed under 42% RHsubsequent conditions, their bud flush was delayed, and subsequent growth rates were lower compared with the lower RHinitial seedlings. When measured at 40% RH, seedlings subjected to lower RHinitial had higher net assimilation rates and stomatal conductance compared with the seedlings acclimated to higher RHinitial humidity. It was concluded that the humidity conditions present during early seedling growth following germination significantly affect their morphological and physiological characteristics during the second growth season.


2016 ◽  
Vol 146 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Hong-Jie Liang ◽  
Xiao-Ming Lu ◽  
Zu-Qing Zhu ◽  
Fu-Xing Zhu

Plant Disease ◽  
2005 ◽  
Vol 89 (11) ◽  
pp. 1241-1241 ◽  
Author(s):  
A. Garibaldi ◽  
A. Minuto ◽  
M. L. Gullino

Several species of Diplotaxis (D. tenuifolia, D. erucoides, and D. muralis), known as wild or sand rocket, are widely cultivated in Italy. Rocket is used in Mediterranean cuisine as salad, a component of packaged salad products, and as a garnish for food. In winter 2003, a severe disease was observed on D. tenuifolia grown in unheated glasshouses on commercial farms near Albenga in northern Italy. Initial symptoms included stem necrosis at the soil level and darkening of leaves. As stem necrosis progressed, infected plants wilted and died. Wilt, characterized by the presence of soft and watery tissues, occurred within a few days on young plants. The disease was extremely severe in the presence of high relative humidity and mild temperature (15°C). Necrotic tissues became covered with white mycelium that produced dark sclerotia. Diseased stem tissue was disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 ppm streptomycin sulfate. Sclerotinia sclerotiorum (1) was consistently recovered from infected stem pieces. Sclerotia observed on infected plants measured 1.23 to 3.00 × 1.40 to 5.38 mm (average 2.10 × 2.85 mm). Sclerotia produced on PDA measured 1.00 to 4.28 × 1.00 to 6.01 mm (average 2.38 × 3.23 mm). Pathogenicity of three isolates obtained from infected plants was confirmed by inoculating 30-day-old plants of D. tenuifolia grown in 18-cm-diameter pots in a glasshouse. Inoculum, 2 g per pot of wheat kernels infested with mycelium and sclerotia of each isolate, was placed on the soil surface around the base of each plant. Three replicates of five pots each were used per isolate. Noninoculated plants served as controls. The inoculation trial was repeated once. All plants were kept at temperatures ranging between 10 and 26°C (average 15°C) with an average relative humidity of 80% and were watered as needed. Inoculated plants developed symptoms of leaf yellowing within 12 days, soon followed by the appearance of white mycelium and sclerotia, and eventually wilted. Control plants remained symptomless. S. sclerotiorum was reisolated from inoculated plants. To our knowledge, this is the first report of infection of D. tenuifolia by S. sclerotiorum in Italy as well as worldwide. The disease currently has been observed in the Liguria Region but not yet in other areas where sand rocket is cultivated. The economic importance of this disease for the crop can be considered medium at the moment, but is expected to increase in the future. Reference: (1) N. F. Buchwald. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift, 75, 1949.


2014 ◽  
Vol 32 (1) ◽  
pp. 31-39
Author(s):  
Joanna Marcinkowska

Seeds of 11 Austrian winter pea genotypes, harvested at Radzików (CEP) in 1993 and 1994, were evaluated for fungi occurrence on Coon's agar medium in Petri plates. Number of species isolated depended on the genotype and year of collection. <i>Alternaria alternata, Stemphylium botryosum</i> were found on all the tested samples and <i>Phoma pinodella</i> and <i>Fusarium poae</i> were also common while <i>Botrytis cinerea, Sclerotinia sclerotiorum</i> and <i>Mycosphaerella pinodes</i> appeared to be common only in 1993. Three species occurred only once. The mycoflora was richer in 1993. The common seed inhabitants usually transmitted higher percentage of fungi than species occuring more seldom.


2004 ◽  
Vol 34 ◽  
pp. 57-66 ◽  
Author(s):  
A. Yilmaz ◽  
M. Ozcan ◽  
B. Ekiz ◽  
A. Ceyhan ◽  
A. Altine

SummaryThis study was carried out to investigate the fertility, milk production and body weight of ewes and the survival and growth characteristics of lambs of the indigenous Imroz and Kivircik sheep breeds. The Imroz and Kivircik sheep breeds are included among the genetic resources in the project for the conservation of the indigenous breeds in Turkey.Conception rates for Imroz and Kivircik ewes were 57.6% and 81.7% respectively, litter sizes were 1.2 and 1.2 respectively, milk yields were 89 kg and 62 kg respectively and average live weights (2–7 years of age) were 43 kg and 55 kg, respectively. Imroz and Kivircik lambs had survival rates at weaning (90th day) of 98% and 96%, birth weights of 3.3 kg and 4.1 kg and weaning weights of 19.8 kg and 28.0 kg, respectively.The results showed that the Kivircik sheep were heavier and the lambs had a better growth rate until weaning than the Imroz breed. However, the milk production of the Imroz ewes was higher than that of Kivircik. The lambs of both breeds had a satisfactory survival and growth rates until weaning and these results might be regarded as a desired adaptation of the Imroz and Kivircik lambs to the environmental conditions of the Marmara Region.


Viruses ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 432 ◽  
Author(s):  
Fangmin Hao ◽  
Mingde Wu ◽  
Guoqing Li

Here, we characterized a negative single-stranded (−ss)RNA mycovirus, Botrytis cinerea mymonavirus 1 (BcMyV1), isolated from the phytopathogenic fungus Botrytis cinerea. The genome of BcMyV1 is 7863 nt in length, possessing three open reading frames (ORF1–3). The ORF1 encodes a large polypeptide containing a conserved mononegaviral RNA-dependent RNA polymerase (RdRp) domain showing homology to the protein L of mymonaviruses, whereas the possible functions of the remaining two ORFs are still unknown. The internal cDNA sequence (10-7829) of BcMyV1 was 97.9% identical to the full-length cDNA sequence of Sclerotinia sclerotiorum negative stranded RNA virus 7 (SsNSRV7), a virus-like contig obtained from Sclerotinia sclerotiorum metatranscriptomes, indicating BcMyV1 should be a strain of SsNSRV7. Phylogenetic analysis based on RdRp domains showed that BcMyV1 was clustered with the viruses in the family Mymonaviridae, suggesting it is a member of Mymonaviridae. BcMyV1 may be widely distributed in regions where B. cinerea occurs in China and even over the world, although it infected only 0.8% of tested B. cinerea strains.


Author(s):  
Г.А. КУПИН ◽  
Т.В. ПЕРШАКОВА ◽  
П.И. КУДИНОВ ◽  
Л.В. МИХАЙЛЮТА ◽  
М.В. БАБАКИНА

Проведены исследования по определению эффективности ингибирующего действия биопрепаратов Экстрасол, Бактофит и Алирин на фитопатогены Sclerotinia sclerotiorum и Botrytis cinerea, вызывающие белую и серую гниль корнеплодов свеклы столовой в процессе хранения. Установлено, что биопрепарат Бактофит имеет наибольшую активность в отношении исследованных фитопатогенных микроорганизмов. Потенциал биопрепарата для контроля порчи свеклы столовой оценивали в опытах in vitro. Ингибирующую способность биопрепарата Бактофит по отношению к Sclerotinia sclerotiorum и Botrytis cinerea исследовали в срезах корнеплодов свеклы при температуре 25°С в течение 7 и 14 сут и при 2°С в течение 7, 14, 28 и 35 сут. Установлено, что после хранения образцов корнеплодов свеклы при температуре 25°C в течение 7 и 14 сут средний диаметр зоны поражения Sclerotinia sclerotiorum в контрольных образцах без внесения Бактофита составил 4,5 и 7,5 мм соответственно; в опытных образцах, зараженных фитопатогенном, но обработанных биопрепаратом, – 2,2 и 4,5 мм соответственно. При температуре хранения 2°C образцов корнеплодов свеклы в течение 7 сут средний диаметр зоны поражения Botrytis cinerea в контрольных образцах составил 1,8 мм, в образцах с внесением биопрепарата признаков развития заболевания не наблюдалось. После хранения образцов корнеплодов свеклы при температуре 2°C через 14, 28 и 35 сут средний диаметр зоны поражения Botrytis cinerea в образцах, не обработанных Бактофитом, составил 3,0; 5,1 и 7,4 мм соответственно; в образцах, прошедших обработку биопрепаратом, – 0,8; 2,0 и 2,5 мм соответственно. Доказана целесообразность применения биопрепарата Бактофит для контроля развития микробиальной порчи свеклы в процессе хранения. Обработка корнеплодов свеклы биопрепаратом Бактофит в сочетании с надлежащими технологиями хранения может снизить количественные и качественные потери продукции растениеводства за счет предотвращения микробиологической порчи. Some investigation were done to define effectiveness of biological preparation Extrasol, Bactofit and Alirin action on phytopathogens Sclerotinia sclerotiorum and Bothrytis cinerea, which cause diseases (white and gray rot) of beetroot during storage. It was stated that biological preparation Bactofit is most active and effective against phytopathogenic microorganisms. Potential of the biopreparation to control beethroot diseases was estimated in in vitro experiments. Antogonistic activity of biological preparations Bactofit against Sclerotinia sclerotiorum and Bothrytis cinerea was investigated in beetroot cut under 25°C during 7 and 14 days and 7, 14, 28 and 35 days under 2°C. It was found that after storage of samples of beet roots at 25°C for 7 and 14 days the mean diameter of the affected area of Sclerotinia sclerotiorum in the control samples without making Bactofit was 4,5 and 7,5 mm, respectively; in the experimental samples infected with pathogenic, but are processed by the biological product, and 2,2 and 4,5 mm, respectively. At a storage temperature of 2°C beet root samples for 7 days, the average diameter of the Botrytis cinerea lesion zone in the control samples was 1,8 mm, in the samples with the introduction of a biopreparation no signs of the disease were observed. After storage of samples of beet root crops at a temperature of 2°C through 14, 28 and 35 days, the average diameter of the lesion zone Botrytis cinerea in samples not treated with Bactophyt was 3,0; 5,1 and 7,4 mm, respectively; in samples treated with a biological product – 0,8; 2,0 and 2,5 mm, respectively.. The feasibility of application of biological Bactofit to control the development of microbial deprivation of the beets during storage proved. Processing beet biologic Bactofit in combination with appropriate storage technologies can reduce quantitative and qualitative losses of crop production by preventing microbial deprivation.


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