scholarly journals Influence of Fruit-to-Fruit Contact on the Susceptibility of French Prune to Infection by Monilinia fructicola

Plant Disease ◽  
1997 ◽  
Vol 81 (12) ◽  
pp. 1416-1424 ◽  
Author(s):  
Themis J. Michailides ◽  
David P. Morgan

In eight commercial prune (Prunus domestica cv. French) orchards, 43 to 69% of brown rot (caused by Monilinia fructicola or M. laxa) infections occurred in clustered fruit as opposed to solitary fruit. Fruit-to-fruit contact surfaces had cracked and thin cuticles and larger microcracks (up to 2,255 μm in length) surrounding the lenticels than those of non-contact surfaces (cracks up to 351 μm in length). Furthermore, fruit-to-fruit contact surfaces retained greater proportions of methylene blue, indicating absence of epicuticular wax, than the non-contact surfaces. Carbohydrate content of exudates in water placed on fruit-to-fruit contact surfaces was 15 and 22 mg/ml, while those of non-contact surfaces were 13 and 19 mg/ml after 15 and 28 h, respectively. Conidia of M. fructicola germinated faster and at higher rates, and the incidence of infection was significantly higher on fruit-to-fruit contact than on non-contact surfaces. Densities of fungal CFU were greater (27 to 98 CFU/cm2) on fruit-to-fruit contact compared to those of non-contact surfaces (7 to 29 CFU/cm2). In four experiments, after spraying to runoff with distilled water, surfaces of solitary fruit dried after 7 to 8 h at 23 ± 1°C compared to 12 to 14 h for groups of 5 to 6 fruit. After spraying the same mature fruit with 1.2 × 105 conidia/ml of M. fructicola and incubating at 24°C and >97% relative humidity, 26 to 70% and 38 to 100% of fruit placed in groups of 5 to 6 were infected after 3 days and 5 days, respectively, whereas only 2 to 13% and 21 to 65% of solitary fruit became infected. These results suggest that fruit-to-fruit contact surfaces predispose prune fruit to infection by M. fructicola, and that it might be possible to reduce fruit losses from brown rot in prune orchards by thinning fruit to reduce fruit clustering, applying early summer fungicide sprays before fruit contact occurs, and ultimately, by selection for non-clustering cultivars in prune breeding programs.

2001 ◽  
Vol 91 (8) ◽  
pp. 759-768 ◽  
Author(s):  
Y. Luo ◽  
D. P. Morgan ◽  
T. J. Michailides

Experiments under controlled environmental conditions were conducted during bloom of prune (Prunus domestica, L.) in 1999 and 2000 to assess the effects of inoculum concentration (IC), wetness duration (WD), temperature, and bloom stages on development of brown rot blossom blight of prunes. Branches from trees of a prune orchard were inoculated with Monilinia fructicola at different bloom stages and incubated at different temperatures with different periods of WD. The proportion of blighted blossoms (PBB) for each inoculated branch was determined. Bloom stage, IC, temperature, and WD significantly affected blossom blight of prunes. PBB at popcorn and full bloom stages was significantly greater than PBB at later bloom stages (P ≤0.05). The optimal temperatures for blossom blight development were 22 to 26°C, and Gaussian functions were used to describe the relationship between PBB and temperature. PBB linearly increased with increased IC. Linear regressions of PBB on WD were obtained for each combination of bloom stage, IC, and temperature. The parameters of these regressions were used in a computer program to produce the possible maximum PBB with 90% probability (PBB90) using stochastic simulations. Early bloom stages with a higher IC at temperatures from 20 to 25°C were associated with more severe blossom blight than late stages with a lower IC at nonoptimal temperatures. Blossom blight did not occur at <10 or >30°C and less than 4-h WD. However, longer than 4-h WD linearly increased incidence of blossom blight. A risk assessment table of blossom blight was produced for different environmental conditions to guide the control of prune brown rot.


2012 ◽  
Vol 75 (10) ◽  
pp. 1883-1889 ◽  
Author(s):  
RAPHAEL SANZIO PIMENTA ◽  
JULIANA F. MOREIRA da SILVA ◽  
JEFFREY S. BUYER ◽  
WOJCIECH J. JANISIEWICZ

Enophytic fungi were isolated from plum (Prunus domestica) leaves, identified with ITS1 and ITS4 primers, and their antagonistic activity was tested against Monilinia fructicola, which causes brown rot, blossom blight, and twig blight of stone fruits, and Colletotrichum gloeosporioides, which causes anthracnose on a variety of fruit crops. The production of antifungal compounds was determined in agar-diffusion and volatile inverted-plate tests. A total of 163 fungi were recovered from 30 plum trees, representing 22 cultivars. Twenty-nine morphotypes were detected, but only 14 species were identified genetically. The most frequently isolated species was Phaeosphaeria nodorum, constituting 86.5% of the total isolates. Four isolates produced inhibitory volatiles to M. fructicola; however, no isolate produced volatiles inhibitory to C. gloeosporioides. The volatiles produced by these fungi were identified as ethyl acetate, 3-methyl-1-butanol, acetic acid, 2-propyn-1-ol, and 2-propenenitrile. The fungal volatiles inhibited growth and reduced width of the hyphae, and caused disintegration of the hyphal content. This is the first study describing fungal endophytes in stone fruits. The P. nodorum strains producing inhibitory volatiles could play a significant role in reduction of M. fructicola expansion in plum tissues. Potential of these strains for biological control of this pathogen on stone fruits warrants further investigation.


2016 ◽  
Vol 11 (3) ◽  
pp. 217
Author(s):  
Estu Nugroho ◽  
Budi Setyono ◽  
Mochammad Su’eb ◽  
Tri Heru Prihadi

Program pemuliaan ikan mas varietas Punten dilakukan dengan seleksi individu terhadap karakter bobot ikan. Pembentukan populasi dasar untuk kegiatan seleksi dilakukan dengan memijahkan secara massal induk ikan mas yang terdiri atas 20 induk betina dan 21 induk jantan yang dikoleksi dari daerah Punten, Kepanjen (delapan betina dan enam jantan), Kediri (tujuh betina dan 12 jantan), Sragen (27 betina dan 10 jantan), dan Blitar (15 betina dan 11 jantan). Larva umur 10 hari dipelihara selama empat bulan. Selanjutnya dilakukan penjarangan sebesar 50% dan benih dipelihara selama 14 bulan untuk dilakukan seleksi dengan panduan hasil sampling 250 ekor individu setiap populasi. Seleksi terhadap calon induk dilakukan saat umur 18 bulan pada populasi jantan dan betina secara terpisah dengan memilih berdasarkan 10% bobot ikan yang terbaik. Calon induk yang terseleksi kemudian dipelihara hingga matang gonad, kemudian dipilih sebanyak 150 pasang dan dipijahkan secara massal. Didapatkan respons positif dari hasil seleksi berdasarkan bobot ikan, yaitu 49,89 g atau 3,66% (populasi ikan jantan) dan 168,47 g atau 11,43% (populasi ikan betina). Nilai heritabilitas untuk bobot ikan adalah 0,238 (jantan) dan 0,505 (betina).Punten carp breeding programs were carried out by individual selection for body weight trait. The base population for selection activities were conducted by mass breeding of parent consisted of 20 female and 21 male collected from area Punten, eight female and six male (Kepanjen), seven female and 12 male (Kediri), 27 female and 10 male (Sragen), 15 female and 11 male (Blitar). Larvae 10 days old reared for four moths. Then after spacing out 50% of total harvest, the offspring reared for 14 months for selection activity based on the sampling of 250 individual each population. Selection of broodstock candidates performed since 18 months age on male and female populations separately by selecting based on 10% of fish with best body weight. Candidates selected broodstocks were then maintained until mature. In oder to produce the next generation 150 pairs were sets and held for mass spawning. The results revealed that selection response were positive, 49.89 g (3.66%) for male and 168.47 (11.43%) for female. Heritability for body weight is 0.238 (male) and 0.505 (female).


Helia ◽  
2001 ◽  
Vol 24 (34) ◽  
pp. 1-16 ◽  
Author(s):  
Domenico Laureti ◽  
Andrea Del Gatto

SUMMARYA total of 245 test cross progenies obtained by crossing cytoplasmic male sterile (CMS) lines and restorer (RHA) lines were evaluated in replicated trials in 1995 and 1997. Experiments were carried out in two locations (Osimo, East Central Italy and Budrio, Northern Italy) in 1995, whereas in 1997 trials were conducted only in Osimo. General combining ability (GCA) and specific combining ability (SCA) of the parents was evaluated to identify genotypes suitable to be used as testers for breeding programs and to verify the performance of hybrids. The results obtained in 1995 were used to make test crosses in 1996 to be evaluated in 1997. The GCA and SCA of RHA and CMS lines were nearly always significant for all the studied traits when lines were randomly taken in 1995. When selected testers were used on the basis of the results of the first year, the SCA of new RHA lines and GCA of new CMS lines were not significant for achene yield, but they were for the other traits.The best GCA estimates for RHA were often higher than those of CMS, indicating that selection for RHA could be more useful than for CMS. As expected, GCA was always lower than SCA. CMS and RHA, with high variance among their test crosses for yield and many other traits, could be used as testers. The lack of a tester with high variance in all traits requires more than one tester in evaluating lines. The GCA of a line can change in function of the germplasm with which it is combined.


2006 ◽  
Vol 57 (4) ◽  
pp. 477 ◽  
Author(s):  
R. De la Rosa ◽  
A. I. Kiran ◽  
D. Barranco ◽  
L. León

The juvenile period represents a serious impediment in olive breeding programs. Seedlings with long juvenile period are of very low interest for the breeder because their evaluation considerably delays the first stages of the breeding process. For this reason, the influence of seedling vigour (measured as plant height or stem diameter) on the characteristics at the adult stage was studied to establish useful negative preselection criteria on the basis of that relationship. Olive progenies from crosses and open pollinations of 12 different parents carried out in 1998 and 1999 were evaluated in the greenhouse and, afterwards, during the first 3 years of bearing in the open field. The results obtained indicate that early evaluation and selection for juvenile period can be performed at the seedling stage in olive progenies on the basis of vigour measurements. Selection for short juvenile period was valid irrespective of parentage and, therefore, could be efficient in a general context. No relationship between juvenile period and yield or fruit traits was found so that this preselection criterion would have no adverse effects on these characters.


2010 ◽  
Vol 23 (2) ◽  
pp. 176-186 ◽  
Author(s):  
Miin-Huey Lee ◽  
Chiu-Min Chiu ◽  
Tatiana Roubtsova ◽  
Chien-Ming Chou ◽  
Richard M. Bostock

A 4.5-kb genomic DNA containing a Monilinia fructicola cutinase gene, MfCUT1, and its flanking regions were isolated and characterized. Sequence analysis revealed that the genomic MfCUT1 carries a 63-bp intron and a promoter region with several transcription factor binding sites that may confer redox regulation of MfCUT1 expression. Redox regulation is indicated by the effect of antioxidants, shown previously to inhibit MfCUT1 gene expression in cutin-induced cultures, and in the present study, where H2O2 enhanced MfCUT1 gene expression. A β-glucuronidase (GUS) reporter gene (gusA) was fused to MfCUT1 under the control of the MfCUT1 promoter, and this construct was then used to generate an MfCUT1-GUS strain by Agrobacterium spp.-mediated transformation. The appearance of GUS activity in response to cutin and suppression of GUS activity by glucose in cutinase-inducing medium verified that the MfCUT1-GUS fusion protein was expressed correctly under the control of the MfCUT1 promoter. MfCUT1-GUS expression was detected following inoculation of peach and apple fruit, peach flower petals, and onion epidermis, and during brown rot symptom development on nectarine fruit at a relatively late stage of infection (24 h postinoculation). However, semiquantitative reverse-transcriptase polymerase chain reaction provided sensitive detection of MfCUT1 expression within 5 h of inoculation in both almond and peach petals. MfCUT1-GUS transformants expressed MfCUT1 transcripts at twice the level as the wild type and caused more severe symptoms on Prunus flower petals, consistent with MfCUT1 contributing to the virulence of M. fructicola.


2021 ◽  
Vol 12 ◽  
Author(s):  
◽  
Aline Fugeray-Scarbel ◽  
Catherine Bastien ◽  
Mathilde Dupont-Nivet ◽  
Stéphane Lemarié

The present study is a transversal analysis of the interest in genomic selection for plant and animal species. It focuses on the arguments that may convince breeders to switch to genomic selection. The arguments are classified into three different “bricks.” The first brick considers the addition of genotyping to improve the accuracy of the prediction of breeding values. The second consists of saving costs and/or shortening the breeding cycle by replacing all or a portion of the phenotyping effort with genotyping. The third concerns population management to improve the choice of parents to either optimize crossbreeding or maintain genetic diversity. We analyse the relevance of these different bricks for a wide range of animal and plant species and sought to explain the differences between species according to their biological specificities and the organization of breeding programs.


Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 389
Author(s):  
Lidia Aparicio-Durán ◽  
Juan M. Arjona-López ◽  
Aurea Hervalejo ◽  
Rocío Calero-Velázquez ◽  
Francisco J. Arenas-Arenas

Phytophthora spp. are one the most common soil-borne pathogens in citrus crops, in which Phytophthoranicotianae and P. citrophthora are the most relevant species, causing disease problems worldwide, such as foot rot and gummosis of the trunk, branch canker, brown rot of fruit, feeder root rot in orchards, and seedling damping-off in nurseries. Phytophthora-tolerant citrus rootstocks are essential for its control and for the success of the citrus industry. The aim of this study was to determine the susceptibility of new citrus rootstocks with low HLB incidence to Phytophthora diseases. Thus, plants of several commercial and new citrus rootstocks originating in different breeding programs were inoculated with an isolate of P. nicotianae. Thirty days post inoculation (DPI), the damage of lesion length in stem was measured for each plant. These results displayed a different susceptibility response to the damage caused by P. nicotianae among the citrus rootstocks tested. Thus, eleven new citrus rootstocks (B11R3T25, B11R5T25, B11R5T49, B11R5T60, B11R5T64, N40R1T18, N40R1T19, N40R3T25, WGFT + 50-7, UFR-6, and CL-5146), which have not been previously studied against Phytophthora diseases, improved the tolerance effect of Carrizo citrange. Our findings provide useful information for citrus growers on rootstock selection to address incidence problems caused by Phytophthora spp.


Plant Disease ◽  
2002 ◽  
Vol 86 (4) ◽  
pp. 443-443 ◽  
Author(s):  
M. Babadoost ◽  
N. Pataky

In August 2001, symptomatic mature fruit of watermelon (Citrullus lanatus) cvs. Crimson Sweet and Royal Sweet were collected from six fields (48 ha) in Iroquois, Kankakee, and Mason counties in Illinois. The fruit surface had dark green, water-soaked lesions, and the rind's epidermis was cracked. Sections of infected rind were examined with a light microscope, and bacterial streaming was observed. Rind tissue was disinfested by rubbing the fruit surface with a paper towel moistened with 70% ethanol. Pieces of rind from the margins of lesions were placed in a test tube containing sterile-distilled water. The tube was shaken, and the suspension was streaked on King's medium B agar in petri plates. The plates were incubated at 26°C for 3 days. A nonfluorescent, gramnegative, anaerobic, oxidase-positive, rod-shaped bacterium was isolated that produced creamy white colonies on nutrient agar. The bacterium was identified as Acidovorax avenae subsp. citrulli based on an enzyme-linked immunosorbent assay test specific for A. avenae subsp. citrulli (kit PSA 14,800; Agdia Inc., Elkhart, IN). The disease was diagnosed as bacterial fruit blotch (1,2). The occurrence of bacterial fruit blotch of watermelon in Illinois is important because (i) watermelon is widely grown in Illinois, (ii) the pathogen also infects melons and pumpkins, and (iii) Illinois grows approximately 1,000 ha of melons and 8,000 ha of pumpkins. References: (1) R. X. Latin. Bacterial fruit blotch. Pages 34-35 in: Compendium of Cucurbit Diseases. The American Phytopathological Society, St. Paul, MN,1996. (2) G. S. Somodi et al. Plant Dis. 75:1053, 1991.


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