Inheritance of Resistance to Cercospora arachidicola and Cercosporidium personatum in Six Virginia-type Peanut Lines1,3

1980 ◽  
Vol 7 (1) ◽  
pp. 4-9 ◽  
Author(s):  
Julia L. Kornegay ◽  
M. K. Beute ◽  
J. C. Wynne

Abstract The inheritance of resistance to two cercospora leaf-spots, Cercospora arachidicola (early leafspot) and Cercosporidium personatum (late leafspot) in Virginia-type peanuts (Arachis hypogaea L.), was determined using F1 and F2 generations and parental lines from a six parent diallel cross under natural field conditions. Two techniques for rating disease severity were employed. General combining ability, determined from both rating techniques, was significant for both F1 and F2 generations, indicating that resistance to both fungi and tolerance to infection i. e., minimal leaf defoliation, was primarily due to additive genetic effects. The six parents produced offspring with different levels of resistance to both fungi. From the estimates of general combining ability effects, only NC-GP 343 and NC 5 produced progeny resistant to both early and late leaf-spot. NC 3033 was resistant to early leafspot, but susceptible to late leafspot. NC-Ac 3139, Florigiant and NC 2 were resistant to late leafspot, but susceptible to early leaf-spot. Disease indices ranked NC 3033 and NC-GP 343 as, overall, the most resistant of the six lines and the most useful to include in a cercospora leafspots resistance breeding program.

2014 ◽  
Vol 12 (1) ◽  
pp. 41-49
Author(s):  
MH Hossain ◽  
I Hossain

A study was conducted to evaluate the effectiveness of three selected botanicals namely leaf extract of Neem (Azadirachta indica), Debdaru (Polyalthia longifolia) and datura (black) (Datura metel) along with Bavistin (Carbendazim) and BAU-biofungicide (Trichoderma harzianum) against leaf spot disease (tikka) of groundnut caused by Cercospora arachidicola and Cercosporidium personatum at the Field Research Farm of Bangladesh Agricultural University, Mymensingh during 2009-10. The most effective treatments were Bavistin, BAU-biofungicide (seed treatment + spray), BAU-biofungicide (spray) and leaf extract of Neem. Bavistin increased pod and dry haulm yield by 53.51 and 24-80 %, respectively. Maximum pod yield and dry haulm weight were recorded under Bavistin. BAU-biofungicide (seed treatment + spray) produced the second highest pod and dry haulm yield followed by leaf extract of Neem and BAU-biofungicide (spray). BAU-biofungicide (seed treatment + spray) and leaf extract of Neem may be recommended for controlling leaf spot disease of groundnut. DOI: http://dx.doi.org/10.3329/agric.v12i1.19579 The Agriculturists 2014; 12(1) 41-49


1998 ◽  
Vol 25 (1) ◽  
pp. 35-39 ◽  
Author(s):  
W. J. Grichar ◽  
B. A. Besler ◽  
A. J. Jaks

Abstract Peanut (Arachis hypogaea L.) pod yield and response to early and late leaf spots [caused by Cercospora arachidicola S. Hori and Cercosporidium personatum (Berk. & M. A. Curtis) Deighton, respectively] were evaluated on six runner-type cultivars under four leaf spot spray programs using tebuconazole at 0.23 kg ai/ha and chlorothalonil at 1.26 kg ai/ha. The four leaf spot spray programs included unsprayed, 14-d schedule, 21-d schedule, and 28-d schedule. With the 14- and 21-d schedule, chlorothalonil was applied at the first and last applications with a maximum of four tebuconazole applications for the middle sprays. On the 28-d schedule, tebuconazole was applied four times. Under conditions of heavy leaf spot disease pressure where no fungicide was applied, Southern Runner and Georgia Browne were slightly less susceptible (although not significantly) to early or late leaf spot than Florunner, GK-7, Georgia Runner, or Sunrunner. Less leaf spot was present in the 14-d schedule compared to 21- or 28-d schedules. Although there was no yield difference between the 14-, 21-, or 28-d schedules, the plots sprayed on a 14-d schedule yielded 43% more than the unsprayed. When averaged across all spray schedules, Georgia Browne yielded 15% more peanuts than Georgia Runner.


1990 ◽  
Vol 115 (4) ◽  
pp. 672-674 ◽  
Author(s):  
C.L. Treat ◽  
W.F. Tracy

Goss's wilt is a bacterial wilt and blight that may cause yield losses up to 50% or greater in sweet corn. Ten hybrids from a diallel cross of five sweet corn (Zea mays L.) inbreds were analyzed for resistance to Goss's wilt (Corynebacterium michiganense ssp. nebraskense Schuster, Hoff, Mandel, and Lazar) in 1987 and 1988. The inbreds used to make the diallel were widely used historically and were chosen on the basis of adaptation and relative maturity. Three hybrids were resistant and seven intermediate, while the field corn controls were extremely susceptible. General combining ability (GCA) and specific combining ability (SCA) sums of squares accounted for 94% and 6% of the variation among crosses, respectively. GCA was highly significant (P ≤ 0.01), while SCA was nonsignificant. Year differences were nonsignificant, but date of rating and hybrid × year interaction effects were significant (P 0.05). Resistance to Goss's wilt is available in sweet corn, and recurrent selection should be effective if improvement in resistance is desired.


1966 ◽  
Vol 46 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Eric D. Putt

Heterosis occurred for the eight plant and seed characters studied. It was most frequent for yield of seed and height of plant. Mean squares for general combining ability (gca) and specific combining ability (sca) were significant (P =.01) for all characters. The estimated components for gca were greater than for sca for days to mature, weight per bushel, and percent oil in the seed; less for height and yield of seed; and essentially the same for days to bloom, diameter of head, and weight per 1000 seeds.The yield of seed and percent oil in the seed, for the highest ranking 100 synthetics that could be composed from the 10 lines, was predicted in F6 assuming 50 and 60% outcrossing between F2 and F6. Virtually all values exceeded the mean performance of four check samples of commercial hybrids. Many exceeded the highest rank check for oil content in the seed. Fourteen of the highest ranking 100 synthetics for yield and 30 for oil content consisted of two or three lines. It was concluded that synthetics can be superior to the present hybrids in heterosis and that desirable synthetics can be made from only a few lines.


2018 ◽  
Vol 10 (10) ◽  
pp. 513
Author(s):  
M. C. Kottayi ◽  
D. D. Saoji ◽  
S. E. Pawar ◽  
A. D. Choudhary

The disease incidence of Cercosporidium personatum in field was analysed in the hybridized population derived from the resistant mutant lines of the cultivar ICGV-87304 and TAG-24 & TG-26. Reciprocal crosses were performed using the same parents. The comparison of disease incidence in hybridized population was made with resistant cultivar Girnar-1. Susceptible parents TAG-24 and TG-26 showed disease incidence of 14.08 and 16.40%, respectively while Girnar-1 and the resistant mutant parents showed percentage infection ranging from 0.06-0.96%. The plants raised from the hybridized population showed the percent infection ranging from 0.01 to 0.02 %.


Plant Disease ◽  
2003 ◽  
Vol 87 (2) ◽  
pp. 203-203
Author(s):  
S. T. Koike ◽  
S. A. Tjosvold ◽  
J. Z. Groenewald ◽  
P. W. Crous

Bells-of-Ireland (Moluccella laevis) (Lamiaceae) is an annual plant that is field planted in coastal California (Santa Cruz County) for commercial cutflower production. In 2001, a new leaf spot disease was found in these commercially grown cutflowers. The disease was most serious in the winter-grown crops in 2001 and 2002, with a few plantings having as much as 100% disease incidence. All other plantings that were surveyed during this time had at least 50% disease. Initial symptoms consisted of gray-green leaf spots. Spots were generally oval in shape, often delimited by the major leaf veins, and later turned tan. Lesions were apparent on both adaxial and abaxial sides of the leaves. A cercosporoid fungus having fasciculate conidiophores, which formed primarily on the abaxial leaf surface, was consistently associated with the spots. Based on morphology and its host, this fungus was initially considered to be Cercospora molucellae Bremer & Petr., which was previously reported on leaves of M. laevis in Turkey (1). However, sequence data obtained from the internal transcribed spacer region (ITS1, ITS2) and the 5.8S gene (STE-U 5110, 5111; GenBank Accession Nos. AY156918 and AY156919) indicated there were no base pair differences between the bells-of-Ireland isolates from California, our own reference isolates of C. apii, as well as GenBank sequences deposited as C. apii. Based on these data, the fungus was subsequently identified as C. apii sensu lato. Pathogenicity was confirmed by spraying a conidial suspension (1.0 × 105 conidia/ml) on leaves of potted bells-of-Ireland plants, incubating the plants in a dew chamber for 24 h, and maintaining them in a greenhouse (23 to 25°C). After 2 weeks, all inoculated plants developed leaf spots that were identical to those observed in the field. C. apii was again associated with all leaf spots. Control plants, which were treated with water, did not develop any symptoms. The test was repeated and the results were similar. To our knowledge this is the first report of C. apii as a pathogen of bells-of-Ireland in California. Reference: (1) C. Chupp. A Monograph of the Fungus Genus Cercospora. Cornell University Press, Ithaca, New York, 1954.


2001 ◽  
Vol 2 (1) ◽  
pp. 1 ◽  
Author(s):  
A. K. Culbreath ◽  
T. B. Brenneman ◽  
R. C. Kemerait

Management of early leaf spot (Cercospora arachidicola) and late leaf spot (Cercosporidium personatum) of peanut (Arachis hypogaea) in the southeastern U.S. is dependent upon multiple applications of foliar fungicides. Field experiments were conducted from 1997 to 2000 to compare the efficacy of mixtures of copper hydroxide or copper oxychloride and reduced rates of chlorothalonil with that of full rates of chlorothalonil alone or chlorothalonil + propiconazole. In all tests, rates per ha of 0.70 kg of chlorothalonil + 0.70 kg of copper oxychloride or higher provided leaf spot control that was similar (P > 0.05) to that achieved with standard rates of chlorothalonil (0.84 kg/ha) + propiconazole (0.063 kg/ha). Application of chlorothalonil at 0.56 kg/ha + copper oxychloride at 0.56 kg/ha controlled leaf spot as well as (P > 0.05) chlorothalonil alone at 1.26 kg/ha in five of six tests in which that treatment was evaluated. In three of four tests in 1998 and 1999, application of chlorothalonil at 0.63 kg/ha + copper hydroxide at 0.63 kg/ha controlled leaf spot as well as chlorothalonil alone at 1.26 kg/ha. In both tests in 2000, application of chlorothalonil at 0.84 kg/ha + copper hydroxide at 0.63 kg/ha controlled leaf spot as well as chlorothalonil alone at 1.26 kg/ha. There were no consistent yield differences among the chlorothalonil, chlorothalonil + propiconazole, or chlorothalonil + copper treatments. Accepted for publication 8 November 2001. Published 16 November 2001.


2013 ◽  
Vol 38 (3) ◽  
pp. 491-503 ◽  
Author(s):  
MH Hossain ◽  
I Hossain

A study was undertaken to evaluate effectiveness of foliar spray with 33 plant extracts against leaf spot (Tikka) of groundnut caused by Cercospora arachidicola and Cercosporidium personatum. Bavistin and BAU-Biofungicide were included in the experiment as checks and spray of plain water represented control. Almost all treatments gave considerable reduction in disease incidence and increase in growth parameters, pod and haulm yield compared to control. The most effective materials were Bavistin 50 WP, BAU-Biofungicide, leaf extract of neem, tomato, datura black, and datura white. The materials decreased spot number per leaf, defoliation per plant, incidence of leaf spot, and number of infected leaf per plant by 35.45 -60.07, 42.06-72.20, 51.97–63.58, and 38.33 to 46.89 % and increased pod yield and haulm yield by 64.37-111.41 and 32.35- 74.71 %, respectively. The materials may be recommended against the disease after economic analysis. DOI: http://dx.doi.org/10.3329/bjar.v38i3.16976 Bangladesh J. Agril. Res. 38(3): 491-503, September 2013


1971 ◽  
Vol 51 (5) ◽  
pp. 377-383 ◽  
Author(s):  
L. P. S. SPANGELO ◽  
R. WATKINS ◽  
C. S. HSU ◽  
S. O. FEJER

General and specific combining abilities were analyzed for total, marketable, early, and late yield, and for flower stalk number in a diallel cross of eight strawberry cultivars. Data were recorded from individual seedlings restricted to two runner plants, thereby eliminating variability resulting from differences in plant density. General and specific combining abilities for the five characters were highly significant. Estimates of general combining ability effects taken alone were, in general, of little value in predicting the order of desirability of individual crosses.


1979 ◽  
Vol 21 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Wai-Koon Tan ◽  
Geok-Yong Tan ◽  
P. D. Walton

Twenty-one progenies and the parents of a 7 × 7 half diallel cross of smooth bromegrass (Bromus inermis Leyss.) were evaluated at four locations in Alberta in each of two years, for genetic variation and genetic by environment interactions in the expression of their yield potentials. Years, locations and their interactions were highly significant in the combined analysis of variance. Combining ability analysis revealed that general combining ability (GCA) and specific combining ability (SCA) were both important in the expression of yield, including spring, fall and annual yield, whereas GCA was more important than SCA for yield per area. Although the genotype × environment interactions were all highly significant, variation accounted for by combining ability effects was generally higher than the interaction effects of GCA and SCA respectively, with environments. High average GCA effects for spring, fall and annual yield were demonstrated for the clones UA5, UA9 and B42. These together with the high average SCA effects suggested that the three clones could be included in a synthetic to develop high yielding cultivars. The results suggested that recurrent selections involving multi-location and multi-year testing seems necessary in breeding for high yielding bromegrass cultivars in Alberta.


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