scholarly journals Differential Response to Foliar Infection with Botrytis cinerea within the Genus Pelargonium

1999 ◽  
Vol 124 (1) ◽  
pp. 76-80 ◽  
Author(s):  
Michael S. Uchneat ◽  
Angelica Zhigilei ◽  
Richard Craig

Foliar evaluations for Botrytis resistance of greenhouse grown plants were performed on 45 cultivars and control genotypes including diploid and tetraploid zonal (P. ×hortorum L.H. Bailey) and ivy (P. peltatum (L.) L'Hér. in Ait.) pelargoniums. Additional evaluations were performed on eight species within section Ciconium and on progeny of a susceptible by susceptible cross-pollination involving the cultivars Ben Franklin and Marilyn. Differential levels of resistance were observed. Among many genotypes that exhibited resistance, two genotypes had consistently high levels of Botrytis resistance over several experiments. These two genotypes were the diploid P. peltatum accession 86-23-1 and the tetraploid P. ×hortorum cultivar Fox. The diploid P. ×hortorum cultivar Ben Franklin was a reliable susceptible control in all experiments. Plants grown outdoors generally had higher levels of resistance than comparable greenhouse grown plants. Orthogonal contrasts indicated no trends in resistance when comparing diploid and tetraploid pelargoniums, or when comparing among ivy, zonal, and floribunda types. Genotypes patented or introduced since 1990 have greater susceptibility than older genotypes. Cross-pollinations among susceptible parents resulted in susceptible progeny, while self-pollinations of a resistant parent resulted in resistant progeny.

2007 ◽  
Vol 21 (2) ◽  
pp. 325-333 ◽  
Author(s):  
Claudia Maria Jacobi ◽  
Mário César Laboissiérè del Sarto

The pollinators and breeding system of two species of Vellozia (Velloziaceae) from high-altitude quartzitic grasslands in SE Brazil were studied. Vellozia leptopetala is shrubby and grows solely on rocky outcrops, V. epidendroides is herbaceous and grows on stony soils. Both bear solitary, hermaphrodite flowers, and have massive, short-lasting annual blooms. We evaluated the level of self-compatibility and need for pollinators of 50 plants of each species and 20-60 flowers per treatment: hand self- and cross-pollination, spontaneous pollination, agamospermy and control. The behavior of floral visitors on flowers and within plants was recorded. Both species are mostly self-incompatible, but produce a small number of seeds by self-fertilization. The pollen-ovule ratio suggests facultative xenogamy. They were visited primarily by bees, of which the most important pollinators were two leaf-cutting bees (Megachile spp.). Vellozia leptopetala was also pollinated by a territorial hummingbird. Low natural seed production compared to cross-pollination seed numbers suggests that pollen limitation is the main cause of low seed set. This was attributed to the combined effect of five mechanisms: selfing prior to anthesis, enhanced geitonogamy as a result of large floral displays, low number of visits per flower for the same reason, pollen theft by many insect species, and, in V. leptopetala, delivery of mixed pollen loads on the stigma as a consequence of hummingbird promiscuity.


Author(s):  
David Novotný ◽  
Jana Brožová ◽  
Pavla Růžičková ◽  
Josef Sus ◽  
Martin Koudela ◽  
...  

In the years 2014 to 2016 the influence of apple tree wood chips and composted apple tree wood chips in which oyster mushroom grew and yielded which were supplemented into soil on strawberry field production and occurrence of grey mould at strawberry (cv. ‘Sonata’) was evaluated. Average weight and number of fruits per plant, average fruit weight, average weight and number of fruits affected by Botrytis cinerea per plant, percentage of weight and number of fruits affected by Botrytis cinerea was calculated. There were recorded differences concerning strawberry yield among the investigated variants of plots, but mainly there were not statistically significant. In 2015 and 2016 the highest average weight of yield and the highest number of fruits was reached at plants cultivated on plots with apple tree wood chips. Average weight of yield on plots with apple tree wood chips was 663.72 g and 822.41 g in 2015 and 2016, respectively. Number of fruits per plant on plots with apple tree wood chips was 67.88 pieces and 65.29 pieces in 2015 and 2016, respectively. Occurrence of grey mould caused by Botrytis cinerea on all variants of plots was similar and small differences was found out only but statistically significant difference was among the years. Grey mould was the most frequently found out in the year 2016. B. cinerea affected 48.27, 56.89 and 55.94 grams of fruits per plant from plots with composted apple tree wood chips, plots with apple tree wood chips and control plots in 2016, respectively.


Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 447 ◽  
Author(s):  
Felipe Valenzuela-Riffo ◽  
Paz E. Zúñiga ◽  
Luis Morales-Quintana ◽  
Mauricio Lolas ◽  
Marcela Cáceres ◽  
...  

Several attempts have been made to study the effects of methyl jasmonate (MeJA) on plants in the past years. However, the comparative effects of the number and phenological time of MeJA applications on the activation of defense systems is currently unknown in strawberries. In the present research, we performed three field treatments during strawberry (Fragaria × ananassa ‘Camarosa’) fruit development and ripening which consisted of differential MeJA applications at flowering (M3), and the large green (M2 and M3) and red ripe (M1, M2, and M3) fruit stages. We also checked changes in gene expression related to plant defense against Botrytis cinerea inoculation post-harvest. In M3 treatment, we observed an upregulation of the anthocyanin and lignin contents and the defense-related genes, encoding for chitinases, β-1,3-glucanases and polygalacturonase-inhibiting proteins, after harvest (0 hpi), along with the jasmonate signaling-related genes FaMYC2 and FaJAZ1 at 48 h after B. cinerea inoculation (48 hpi) during postharvest storage. Although we did not find differences in gray mold incidence between the MeJA treatments and control, these results suggest that preharvest MeJA treatment from the flowering stage onwards (M3) primes defense responses mediated by the upregulation of different defense-related genes and retains the upregulation of MYC2 and JAZ1 at 48 hpi.


2019 ◽  
Vol 17 (6) ◽  
pp. 514-521
Author(s):  
Karen K. Fugate ◽  
Larry G. Campbell ◽  
Giovanny Covarrubias-Pazaran ◽  
Lorraine Rodriguez-Bonilla ◽  
Juan Zalapa

AbstractGermplasm lines with resistance to the sugarbeet root maggot (SBRM) have been developed and released to the public, providing a means to generate hybrids with resistance against the most devastating insect pest of sugarbeet in North America. Effective use of this germplasm, however, requires knowledge of relative strengths of SBRM resistance between lines and knowledge of the diversity and genetic relationships between germplasm. Therefore, field studies comparing SBRM resistance of four released SBRM-resistant germplasm lines (F1015, F1016, F1024 and F1043), a SBRM-resistant parent (PI 179180) and an unreleased SBRM-resistant population (F1055) were performed, and genetic analysis of the diversity and relationships between SBRM-resistant germplasm and their available parents was conducted using simple sequence repeat (SSR) markers. Under natural SBRM infestations, resistant germplasm exhibited significantly less SBRM damage than a susceptible control, with similar, high levels of resistance in F1016, F1024, F1043, F1055 and PI 179180 and lower resistance in F1015. SSR analysis revealed genetic similarities between F1016, F1024 and F1055, while F1015 and F1043 were genetically distinct from these lines. Among resistant genotypes, F1015 and F1043 exhibited greatest and least within-line genetic diversity, indicating greater and lesser inbreeding for F1043 and F1015, respectively. Similarities in damage ratings and genetics for F1016, F1024 and F1055 indicate that these lines are likely to be equally effective at introducing SBRM resistance into elite populations and in combining ability. In contrast, F1043, with its unique parentage and genetic dissimilarity from other resistant lines, provides a genetically distinct, but similarly effective, source of SBRM resistance.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 565d-565
Author(s):  
Michael S. Uchneat ◽  
Richard Craig

Botrytis cinerea is an economically important fungal pathogen of Pelargonium species. We are currently studying this plant–pathogen interaction to identify mechanisms of host resistance. Our ultimate objective is to develop commercial Pelargonium genotypes with enhanced resistance to this pathogen. Though all stages of production may be affected by this pathogen, we are investigating foliar and floral resistance of mature plants. Through simple assays, over 200 genotypes have been evaluated for foliar resistance, and more than 100 genotypes have been evaluated for floral resistance. Resistant and susceptible control genotypes have been identified for diploid and tetraploid P. ×hortorum and P. peltatum; these genotypes are being investigated to elucidate mechanisms of resistance. The diploid ivy accession 86-23-1 and the tetraploid zonal geranium `Fox' have the greatest foliar resistance among the genotypes evaluated. The diploid P. ×hortorum `Ben Franklin' has the greatest floral resistance among the evaluated genotypes. Foliar and floral resistance appear to be inherited as separate traits. Foliar resistance is manifested as a two day delay in symptom expression when compared to susceptible genotypes. Foliar resistant accession 86-23-1 has a cuticle with 150% the mass of other Pelargonium genotypes. This difference may be responsible for the observed resistance. Cuticle mass does not appear to be important in floral resistance.


1979 ◽  
Vol 236 (2) ◽  
pp. H301-H306 ◽  
Author(s):  
S. Sullivan ◽  
H. V. Sparks

We investigated the responsiveness of isolated diabetic and normal rabbit aortic strips to norepinephrine. Alloxan, 160 mg/kg, was administered intravenously 1 mo before experiments were performed. Helically cut thoracic aortic strips from diabetic and control animals were suspended side by side in the same muscle bath. The maximum contractile response to norepinephrine of diabetic strips was 68 +/- 5% of control in eight pairs of animals (P less than 0.001). This differential response was not changed by propranolol or cocaine, indicating that it is not explained by either enhanced beta receptor activity or more avid uptake of norepinephrine by nerve endings. Tyramine responses displayed the same differential, suggesting that endogenous release of norepinephrine also results in a lower response of diabetic aortic strips. Maximum responses to KCl were also markedly depressed in strips from nine diabetic rabbits (P less than 0.005). This indicates that the diabetes-induced changes occur at a stage in contraction beyond alpha-receptor activation.


1995 ◽  
Vol 25 (5) ◽  
pp. 844-850
Author(s):  
Steven A. Knowe

An evaluation of six objective estimators of treatment efficacy for bigleaf maple (Acermacrophyllum Pursh) was made on the basis of data from two herbicide screening studies. The estimators were evaluated for sensitivity to statistical comparison of treatment means. Evaluation was made on the basis of (i) overall mean and coefficient of variation for percent change in crown volume, as well as (ii) percent control based on regression-adjusted post-treatment crown height, (iii) crown diameter, (iv) crown profile, (v) crown area, and (vi) crown volume. Estimates of overall mean control were similar among the expressions of crown size, but the estimate based on change in crown volume was substantially lower. The coefficient of variation was smallest when control was calculated from crown height or crown profile and was largest for change in crown volume. Orthogonal contrasts indicated that control calculated from one- and two-dimensional expressions of crown size tended to be more sensitive to treatment differences than other expressions of crown size. Change in crown volume and control calculated from crown volume tended to be the least sensitive to treatment differences, resulting in rejection of the null hypothesis for fewer orthogonal contrasts. These results for bigleaf maple are consistent with the results obtained for several hardwood species in the southeastern United States.


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