scholarly journals Genetic control of resistance to gray leaf spot of maize in tropical germplasm

2012 ◽  
Vol 12 (2) ◽  
pp. 145-150 ◽  
Author(s):  
André Humberto de Brito ◽  
Livia Maria Chamma Davide ◽  
Renzo Garcia Von Pinho ◽  
Rafael Pelloso de Carvalho ◽  
Matheus Costa dos Reis
Keyword(s):  
Genetic Control ◽  
Leaf Spot ◽  
Genetic Model ◽  
Block Design ◽  
Gray Leaf Spot ◽  
Cercospora Leaf Spot ◽  
Gene Effects ◽  
Randomized Block Design ◽  
Tropical Germplasm ◽  
Plant Level

The main goal of this study was to assess the nature and magnitude of gene effects for resistance to Cercospora leaf spot. A randomized block design with three replications was used. The data were obtained at the plant level by assessing the disease severity. The data were analyzed per experiment, using the average data per plot. A dominant-additive genetic model without epistasis was considered, with estimation of the components of means and variance. The genetic control of resistance to gray leaf spot is polygenic with predominance of the additive effects. Dominance was observed in a few small-effect loci and high heritability values.

scholarly journals Inheritance of resistance to anthracnose stalk rot (Colletotrichum graminicola) in tropical maize inbred lines

2012 ◽  
Vol 12 (3) ◽  
pp. 179-184 ◽  
Author(s):  
Rodrigo Rodrigues Matiello ◽  
Kátia Regiane Brunelli ◽  
Maria Teresa Gomes Lopes ◽  
Regina Mélo Sartori Coêlho Morello ◽  
Herberte Pereira da Silva ◽  
...  
Keyword(s):  
Genetic Model ◽  
Block Design ◽  
Dominant Gene ◽  
Lesion Length ◽  
Inheritance Of Resistance ◽  
Colletotrichum Graminicola ◽  
Tropical Maize ◽  
Gene Effects ◽  
Stalk Rot ◽  
Randomized Block Design

Generation means was used to study the mode of inheritance of resistance to anthracnose stalk rot in tropical maize. Each population was comprised of six generations in two trials under a randomized block design. Inoculations were performed using a suspension of 10(5) conidia mL-1 applied into the stalk. Internal lesion length was directly measured by opening the stalk thirty days after inoculation. Results indicated contrasting modes of inheritance. In one population, dominant gene effects predominated. Besides, additive x dominant and additive x additive interactions were also found. Intermediate values of heritability indicated a complex resistance inheritance probably conditioned by several genes of small effects. An additive-dominant genetic model sufficed to explain the variation in the second population, where additive gene effects predominated. Few genes of major effects control disease resistance in this cross. Heterosis widely differed between populations, which can be attributed to the genetic background of the parental resistant lines.

scholarly journals Generation Mean Analysis in Cowpea [Vigna unguiculata (L.) Walp.] under Flower Thrips infestation

2018 ◽  
Vol 10 (4) ◽  
pp. 86 ◽  
Author(s):  
Gonné Sobda ◽  
Fonji Maureen Atemkeng ◽  
Ousmane Boukar ◽  
Chistian Fatokun ◽  
Pangirayi Bernard Tongoona ◽  
...  
Keyword(s):  
Block Design ◽  
Generation Mean Analysis ◽  
Flower Number ◽  
Narrow Sense Heritability ◽  
Gene Effects ◽  
Flower Thrips ◽  
Randomized Block Design ◽  
Cowpea Resistance ◽  
Predominant Type ◽  
Screen House

Two sets of six generations (P1, P2, F1, F2, BC1P1, BC1P2) of cowpea were developed from crosses of contrasting inbred lines VYA (susceptible) × SANZI (resistant) and LORI (susceptible) × SANZI (resistant). The aim of this study was to determine the inheritance and elucidate the genetic control of cowpea resistance to thrips. The first set (VYA × SANZI) was evaluated under natural thrips infestation in the field in a completely randomized block design with three replications. The second set (LORI × SANZI) was screened using artificial thrips infestation in the screen house. In each trial, data were recorded on 150 individual plants. These included the score of thrips damages using the scale of one to nine, number of thrips per flower, number of pods per plant, pod weight per plant and grain weight per plant. The generation mean analysis revealed that both additive and non-additive types of gene effects were significant. Dominance × dominance was the most predominant type of gene effects for thrips resistance, suggesting that breeders should delay selection to late generations to allow advancement of as many high-potential recombinants as possible during hybridization. The number of genes that control the expression of number of thrips per flower was three and ranged from three to four, for score of thrips damages. High broad sense and moderate narrow sense heritability were observed ranging from 0.53 to 0.65 and 0.14 to 0.36, respectively for all of the traits measured. 

scholarly journals Identification and characterization of maize lines resistant to leaf diseases

2019 ◽  
Vol 40 (2) ◽  
pp. 517
Author(s):  
Kaian Albino Corazza Kaefer ◽  
Adilson Ricken Schuelter ◽  
Ivan Schuster ◽  
Jonatas Marcolin ◽  
Eliane Cristina Gruszka Vendruscolo
Keyword(s):  
Genetic Diversity ◽  
Leaf Spot ◽  
Block Design ◽  
Snp Markers ◽  
Gray Leaf Spot ◽  
Leaf Blight ◽  
Yield Reduction ◽  
Northern Leaf Blight ◽  
Sources Of Resistance ◽  
White Leaf

Among the maize leaf diseases, white leaf spot, northern leaf blight, gray leaf spot, and southern rust are recognized not only by the potential for grain yield reduction but also by the widespread occurrence in the producing regions of Brazil and the world. The aim of this study was to characterize common maize lines for resistance to white leaf spot, northern leaf blight, gray leaf spot, and southern rust and suggest crosses based on the genetic diversity detected in SNP markers. The experiment was conducted in a randomized block design with three replications in order to characterize 72 maize lines. Genotypic values were predicted using the REML/BLUP procedure. These 72 lines were genotyped with SNP markers using the 650K platform (Affymetrix®) for the assessment of the genetic diversity. Genetic diversity was quantified using the Tocher and UPGMA methods. The existence of genetic variability for disease resistance was detected among maize lines, which made possible to classify them into three large groups (I, II, and III). The maize lines CD 49 and CD50 showed a good performance and can be considered sources of resistance to diseases. Therefore, their use as gene donors in maize breeding programs is recommended. Considering the information of genetic distance together with high heritability for leaf diseases, backcrossing of parent genotypes with different resistance levels, such as those of the lines CD49 x CD69 and CD50 x CD16, may result in new gene combinations, as they are divergent and meet good performances.

scholarly journals Calcium and potassium contents in nutrient solution on Phoma leaf spot intensity in coffee seedlings

Revista CERES ◽  
2016 ◽  
Vol 63 (4) ◽  
pp. 486-491 ◽  
Author(s):  
Aricléia de Moraes Catarino ◽  
Edson Ampélio Pozza ◽  
Adélia Aziz Alexandre Pozza ◽  
Leone Stabile dias Santos ◽  
Gabriel Brandão Vasco ◽  
...  
Keyword(s):  
Nutrient Solution ◽  
Leaf Spot ◽  
Block Design ◽  
Fungal Diseases ◽  
Growth Chamber ◽  
Spot Intensity ◽  
Controlled Conditions ◽  
Progress Curve ◽  
Randomized Block Design ◽  
Nutrient Solutions

ABSTRACT Coffee is one of the main export commodities of Brazilian agribusiness. Phoma leaf spot [Phoma tarda (Stewart) Boerema & Bollen] is one of the most important coffee fungal diseases in Brazil. Therefore, this study aimed to evaluate the intensity of Phoma leaf spot in coffee seedlings supplied with different rates of Ca+2 and K+. The study was conducted under controlled conditions in a growth chamber, at the Department of Phytopathology - UFLA, from February 2010 to December 2011. The assay was repeated twice under the same conditions. The nutrient solutions consisted of five concentrations of K+ (3, 4, 5, 6, 7 mmol L-1) and Ca+2 (2, 4, 6, 8 and 10 mmol L-1). The experiment was arranged in a randomized block design, with 25 treatments and three replicates, with two plants per plot. The areas under incidence progress curve (AUIPC) and severity (AUSPC) were calculated. At the lowest rate of Ca2+ (2 mmol L-1) and highest K+ (6 and 7 mmol L-1), approximately, the AUIPC was the smallest. For the AUSPC, the lowest rates of Ca+2 and K+ resulted in the lowest severities. Supply of Ca+2 and K+ in nutrient solution reduced AUIPC and AUSPC of Phoma leaf spot, and these nutrients can be recommended for the management of the disease.

Evaluation of genetic potential of shoot fly resistant sources in sorghum (Sorghum bicolor (L.) Moench)

2008 ◽  
Vol 147 (1) ◽  
pp. 71-80 ◽  
Author(s):  
C. ARUNA ◽  
P. G. PADMAJA
Keyword(s):  
Block Design ◽  
Trichome Density ◽  
Male Sterile ◽  
Seedling Vigour ◽  
Gene Effects ◽  
Shoot Fly ◽  
Randomized Block Design ◽  
Sorghum Shoot Fly ◽  
Additive Gene ◽  
And Cluster Analysis

SUMMARYTwelve sorghum lines resistant to sorghum shoot fly were evaluated for their combining ability for shoot fly resistance and traits associated with resistance, using three male sterile lines in two environments. Using a completely randomized block design with three replications, 36 hybrids and 15 parental genotypes were raised. Considerable genetic variation was observed for all the traits studied. Non-additive gene effects played an important role in governing glossiness, seedling vigour and proportion of plants with deadhearts. For trichome density, both additive and non-additive gene actions were important. Among the lines evaluated, those identified to be good combiners were SFCR 1047 for seedling vigour, deadheart proportion and trichome density, RSE 03 for glossiness, deadheart proportion at 21 DAE and trichome density, and SPSFR 94032 for seedling vigour and shoot fly eggs per plant. Genetic diversity and cluster analysis grouped the 15 parents (12 resistant and 3 susceptible parents) into five clusters. Utilization of the resistant lines belonging to different clusters in improving shoot fly resistance in sorghum is discussed.

scholarly journals Expression of Heterosis for Productive Traits in Bottle Gourd Hybrids

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
AKM Quamruzzaman ◽  
M.M.R. SALIM ◽  
L. AKHTER ◽  
M.M. RAHMAN ◽  
M.A. Z. CHOWDHURY
Keyword(s):  
Agricultural Research ◽  
Block Design ◽  
Diallel Cross ◽  
Bottle Gourd ◽  
Research Centre ◽  
Gene Effects ◽  
Randomized Block Design ◽  
Additive Gene ◽  
The Cross ◽  
Productive Traits

A study was conducted in bottle gourd to estimate the magnitude of heterosis for yield and its thirteen yield related components. Twenty one bottle gourd hybrids generated from 7 × 7 diallel cross (excluding reciprocals) along with their seven parents evaluated in a Randomized Block Design with three replication at at the Olericulture Division of Horticulture Research Centre, Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh during 2018-19. Most of the crosses showed significant heterobeltiosis for earliness. The highest heterobeltiotic effect was observed in the cross P2XP7 and P4XP7. The best heterotic cross for fruit length was P4XP5. Maximum heterotic effect in respect of fruit number per plant was found in the cross P1XP6 and P4XP6. In terms of yield per plant the highest heterobeltiosis was shown by the crosses P3XP4, P3XP5, P4XP5 and P4XP7. In the overall analysis, both additive and non-additive gene actions were found important with predominance of the additive gene effects in the inheritance of bottle gourd.

scholarly journals Uji Infektifitas dan Efektifitas Rhizobia sp. terhadap Tanaman Kedelai di Rumah Kasa pada Tanah Ultisol dengan pH yang Berbeda

2018 ◽  
Vol 5 (1) ◽  
pp. 75-87
Author(s):  
M. Reza Alfikri ◽  
Hardy Guchi ◽  
Asmarlaili Sahar Hanafiah
Keyword(s):  
Root Nodule ◽  
Block Design ◽  
Soil Biology ◽  
Fixed Nitrogen ◽  
N Level ◽  
Randomized Block Design ◽  
Plant Level ◽  
Biology Laboratory ◽  
Screen House ◽  
Infectivity Test

Rhizobia fixed nitrogen from the air and supplied legume and effected to soil fertility. The research was conducted in May 2017 until November at Soil Biology Laboratory and Screen House of Agriculture Faculty University of Sumatera Utara. This research was carried out with 2 stages: growth test at various pH with isolate tested (TJA 1, TJA 2, TJA 3, BGR 1, BGR 2, BGR 3, BGR 4, BALAI 1, BALAI 2, BALAI 3, LP 1, LP 2, LP 3, LP 4 and LAB) and the infectivity test and the effectivity of Rhizobia. The research used Randomized Block Design with 2 treatment: Lime (Without Lime and Lime 1 x Aldd) and Isolate Rhizobia (TJA 1, TJA 3, BGR 1, BGR 3, BGR 4, BALAI 2, BALAI 3, LP 1, LP 2, LP 4 and LAB). The application of Rhizobia’s isolate BGR 3 showed the infektively with root nodule amount criteria(124,00). The isolate Rhizobia’s BGR 3 effectively increased N plant level and N absorption (3,80 %; 31,08mg/plant). Application of isolate Rhizobia was not able to increase the level of P plants and P plant uptake. The best interaction was shown (Plant height 85.00 cm, stem diameter 3.93 mm, root nodule 127.50, N level of 3.80%, N absorption 30.16 mg / plant) by treatment of BGR 3 and Lime 1 x Aldd.

scholarly journals Keefektifan beberapa senyawa kimia sebagai agen penginduksi resistensi tanaman sawi terhadap penyakit bercak daun Curvularia

Jurnal Agro ◽  
10.15575/4619 ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 86-94
Author(s):  
Tarkus Suganda ◽  
Dinda Yulindar Wulandari
Keyword(s):  
Salicylic Acid ◽  
Leaf Spot ◽  
Block Design ◽  
Vitamin B1 ◽  
Conidial Suspension ◽  
Chemical Inducers ◽  
Green Leaves ◽  
Randomized Block Design ◽  
Resistance Inducers ◽  
Mustard Green

Penyakit bercak daun Curvularia merupakan penyakit baru pada tanaman sawi. Pengendalian penyakit dengan fungisida sintetik sangat berbahaya karena daun sawi dikonsumsi sebagai sayuran mentah atau pengolahan minimal, untuk itu diperlukan alternatif cara pengendalian yang lebih aman bagi kesehatan seperti menginduksi resistensi tanaman menggunakan bahan kimia. Penelitian ini bertujuan untuk mengetahui keefektifan beberapa bahan penginduksi resistensi seperti asam salisilat, kitin, K2HPO4, dan vitamin B1. Sementara, Bion M1/48, bahan penginduksi komersial, digunakan sebagai pembanding. Bahan penginduksi diaplikasikan melalui cara perendaman benih dan disemprotkan. Pada perlakuan perendaman, benih direndam dalam suspensi bahan penginduksi selama 12 jam, sedangkan pada perlakuan penyemprotan, bahan penginduksi disemprotkan satu kali yaitu dua hari sebelum inokulasi dilakukan. Inokulasi patogen yang digunakan memiliki suspensi konidia kerapatan 5 x 105 konidia ml-1. Penelitian ini menggunakan Rancangan Acak Kelompok dengan empat  ulangan. Pengamatan dilakukan terhadap masa inkubasi dan intensitas penyakit. Hasil pengujian menunjukkan bahwa perendaman benih asam salisilat, kitin dan K2HPO4, mampu menunda kemunculan gejala sakit lebih lama dibandingkan Bion M 1/48. Terhadap intensitas penyakit, asam salisilat, kitin, dan K2HPO4, juga efektif menginduksi resistensi tanaman sawi terhadap penyakit bercak daun Curvularia. Ketiga senyawa kimia ini potensial untuk digunakan sebagai pengganti fungisida sintetis dalam mengendalikan penyakit bercak daun Curvularia pada tanaman sawi.ABSTRACTCurvularia leaf spot is a new disease on mustard green (Brassica juncea L.). The diseases control with synthetic fungicide is dangerous since mustard green leaves are freshly consumed or with minimum treatments. Therefore, a safer alternative method must be sought such inducing plant resistance using chemical inducers. This research aimed to evaluate effectiveness of salicylic acid, chitin, K2HPO4, vitamin B1, as resistance inducers. Meanwhile,  Bion M 1/48, a commercial inducer, was used as the check treatment. These substances were applied as either seed soaking or spraying. In the soaking treatmet, the seeds were soaked for 12 hours duration, whereas in the spraying treatment, chemicals were applied once, at two days before inoculation with conidial suspension of 5 x 105 conidia ml-1. Experimental plants were arranged in a Randomized Block Design with four replicates. Observation was carried out on incubation period and disease intensity. Results showed that soaking the seed in salicylic acid, chitin and K2HPO4 was able to delay the appearance of symptoms, better than of Bion M 1/48. Towards disease intensity, salicylic acid, chitin, and K2HPO4 were also effective in inducing resistance of mustard green leaves against Curvularia leaf spot.  The three substances were potential to be applied as an alternative to synthetic fungicide in managing Curvularia leaf spot on the mustard green.

scholarly journals KAJIAN MACAM PUPUK HAYATI TERHADAP INTENSITAS PENYAKIT BERCAK DAUN Cercospora sp PADA TANAMAN JAGUNG HITAM

2020 ◽  
Vol 22 (1) ◽  
pp. 50
Author(s):  
Nining Saputri ◽  
Sartono Joko Santosa ◽  
Saiful Bahri
Keyword(s):  
Leaf Spot ◽  
Block Design ◽  
Leaf Spot Disease ◽  
Spot Disease ◽  
Corn Husk ◽  
Central Java ◽  
Leaf Spots ◽  
Randomized Block Design ◽  
Disease Attack ◽  
Biological Fertilizer

This study is titled Study of Biological Fertilizers on the intensity of Leaf Spots (Cercospora sp.) On Black Corn (Black Aztec) with the aim to study the types of biological fertilizers on the intensity of Cercospora sp. which began on November 9, 2019, in Jembangan Village, Gagaksipat Village, Ngemplak District, Boyolali District, Central Java, with a height of 150m (asl). This study uses a single factor Complete Randomized Block Design (RCBD) consisting of 10 treatments and 3 replications. The data from the results of this study were analyzed with the Duncan at the 5% level. The parameters observed include: intensity of leaf spot disease, weight of cob with corn husk per plant (gram), weight of cob without corn husk per plant (gram), weight of 100 corn seeds (gram). The results showed that: (1) Symptoms of leaf spot disease appear evenly on all biological fertilizers, symptoms of disease attack began to appear at the age of 30 days after planting. (2) In the treatment of biological fertilizer Megharizo on black corn concertration 10 ml/1,2 l (B2) can reduce the intensity of leaf spot disease. (3) The application of biological fertilizer from three doses has not been able to increase the yield of black corn to the weight of corn with corn husk, weight of corn without corn husk, and weight of 100 seeds.

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