scholarly journals Genotypic and Phenotypic Correlations between Leaf-Rust Disease and Leaf Morphology and its Ratio in Arabica Coffee

2020 ◽  
Vol 25 (3) ◽  
pp. 468-477
Author(s):  
Sabam Malau

  Selection parameter in coffee breeding for leaf rust (Hemeleia vastatrix) resistance is very important. Breeders used leaf-rust severity and leaf-rust incidence as parameters of direct selection. However, scientific proof is not yet available whether leaf morphology can be used as a parameter of indirect selection. The objective of this research was to seek the possibility of leaf morphology parameter and its ratio to be used as selection criteria through analyses of genotypic and phenotypic correlations of parameter of rust disease and parameter of leaf morphology and its ratio. The result revealed that genotypes showed significant variations in leaf-rust severity (5.21–25.84%), leaf morphology, and leaf-morphology ratio. Leaf length to leaf width ratio, leaf length to leaf area ratio, and leaf width to leaf weight ratio were not affected by the environment. Leaf-rust severity performed highly significant positive genotypic and phenotypic correlations the ratio of with leaf length to leaf area. For selection criteria, leaf-rust severity could be better used rather than leaf-rust incidence and branch-rust incidence. The ratio of leaf length to leaf area could also be used as an indirect selection criterion because the ratio showed a highly significant genotypic correlation with leaf-rust severity (rGab = 0.254**). However, the ratio of leaf length to leaf area is even better chosen for selection criteria rather than leaf-rust severity because the ratio was not affected by the environment.   Keywords: fungus, Hemeleia vastatrix, indirect selection

2022 ◽  
Vol 951 (1) ◽  
pp. 012056
Author(s):  
S Malau ◽  
M R Sihotang

Abstract Coffee leaf rust (CLR) is a pandemic and a serious threat for coffee sustainability in many coffee producing countries. To overcome this CLR, the world’s consensus is to use of resistant cultivars which can be created through coffee breeding program. This research aimed to study genotypic and phenotypic correlations between CLR symptoms of seven arabica coffee (Coffea arabica L.) genotypes that were selected from different districts of North Sumatra Province, Indonesia. This experimental research using a randomized complete block design with three replications was conducted at the experimental garden of the Faculty of Agriculture, Universitas HKBP Nommensen in Medan. The result of this study indicate that leaf rust severity (LRS) had a genotypic component variance of 86.8% which indicated that LRS was controlled more dominantly by plant genetics than other unknown factors. Severity indicated by LRS showed no genotypic and phenotypic correlation with dispersal indicated by branch rust incidence (BRI) and leaf rust incidence (LRI). BRI genotypically correlated with LRI. The results of this study could contribute to resistance coffee breeding for CLR.


2021 ◽  
Vol 748 (1) ◽  
pp. 012002
Author(s):  
Sabam Malau ◽  
Albiner Siagian ◽  
Maria Rumondang Sihotang

Abstract Coffee is now experiencing a serious threat from fungus Hemileia vastatrix which caused epidemic of rust disease in America, Africa, and Asia. As solution, the use of resistant cultivars is the best way. However, interaction between genotype and environment can change the rank of genotypes that shows instability of these genotypes against leaf rust. Purpose of this research was to study stability of genotypes of Arabica coffee against coffee leaf rust. A field experiment was arranged as factorial randomized complete block design with 2 factors (genotypes and climate zones) with three replication. The observed parameters were branch rust incidence, leaf rust incidence, and leaf rust severity. This research result showed significant genotype x environment interaction in all variables. Length of dry season is the most important factor affecting coffee leaf rust because it had the highest correlation coefficient with leaf rust severity (r = 0.662**). Less length of dry season should be the first criteria for selection of coffee farms. The most desired genotype was G7 which performed low leaf rust severity (7.71%) and had a stable resistance indicated by the same leaf rust severity in all environments and 6 SMg. Due to the significant interaction between genotypes and the environment, the genotype to be planted in a region must be tested in that region first.


1983 ◽  
Vol 34 (1) ◽  
pp. 47 ◽  
Author(s):  
R Evans ◽  
BJ McGuirk

To assess the value of skin and fleece characters as potential indirect selection criteria for increased resistance to fleece rot, estimates of the genetic correlations between the skin and fleece characters and fleece rot are needed. The characters most likely to be useful can be identified relatively cheaply and quickly by estimating the phenotypic correlation with fleece rot. This paper illustrates how phenotypic correlations with fleece rot, scored as an all-or-none character, can be estimated retrospectively from published estimates of means and standard deviations of fleece and skin characters measured in groups of sheep affected by or free from fleece rot. The paper emphasizes the incidence-dependent nature of the correlation coefficient so obtained, and points out that this must be allowed for when comparisons of correlations are made between flocks in which the incidence of fleece rot differs. This problem can be avoided by using the concept of liability to fleece rot. Data from three recently published papers are used to illustrate the main points.


2019 ◽  
Vol 6 (2) ◽  
pp. 69
Author(s):  
Sabam Malau

<p>Coffee leaf rust disease (<em>Hemileia vastatrix</em>) causes large damage to Arabica coffee plantation in Asia, Africa, and America.  In Indonesia, particularly in North Sumatra, the resistance level of Arabica coffee genotypes is still unknown. The objective of this research was to determine the resistance variability of Arabica coffee genotypes to leaf rust disease and its relation to leaf morphology.  A total of 84 genotypes grown in North Sumatra were selected in November 2015 and 2016, and December 2017 using a nested design.  Data were analyzed using nested design, correlation, stepwise regression, and cluster hierarchy analysis. The result showed that the G56 genotype performed the most resistant to leaf rust disease, with a severity of 5.21%.  The severity of leaf rust disease has high genotypic variation, low heritability, and high genetic advance.  Leaf morphological ratios showed moderate to high genotypic variation and heritability.  The severity of leaf rust (y) significantly correlated with the ratio of leaf length to leaf area (x<sub>1</sub>) and the ratio of leaf length to leaf width (x<sub>2</sub>) with the equation y = 2.04 + 62.48x<sub>1 </sub>- 3.95x<sub>2,</sub> and multiple correlation coefficients R = 0.470 **. By using the leaf rust severity and the two ratios in the cluster analysis, these 84 genotypes were grouped into five clusters.  The result showed that several Arabica coffee genotypes with a high level of resistance to leaf rust disease are potential to be further developed.</p>


2017 ◽  
Vol 29 (1) ◽  
pp. 117
Author(s):  
Ghulam M.U. Din ◽  
Amjad Ali ◽  
Amjad Abbas ◽  
Muhammad Naveed ◽  
Javed Anwar ◽  
...  

Leaf rust of wheat caused by Puccinia triticina is one of the most important diseases in the Pakistan and cause both yield and quality reduction. To investigate the effect of leaf rust of wheat on morph-physiological processes and grain yield, a field experiment was conducted using different wheat lines and varieties. The morpho-physiological attributes of the infected plant leaves were badly affected by the infection of leaf rust of wheat. The experiment comprised two treatments, one was inoculated with leaf rust spores manually and Morocco as a spreader while other keeping as a control. The results showed that there was -42.92, -23.72, -23.01, and -11.42, % decrease in chlorophyll content, flag leaf area, specific flag leaf area and relative water content in leaf rust (diseased) plot respectively while 21.24, 160.16% increase in relative dry weight and relative membrane permeability in the leaf rust plot. The results also revealed that leaf rust of wheat also reduces the yield components like number of grains per spike, spike length and 1000 grain weight (-52.38, -43.37 and -45.50 respectively). Thus, it could be concluded that leaf rust of wheat affect the morph-physiological process of wheat plants and badly reduce the yield as well.


2020 ◽  
Vol 8 (1) ◽  
pp. 21
Author(s):  
Sabam Malau

Coffee leaf rust (Hemileia vastatrix) caused large damage on Arabica coffee in Asia, Africa, and America. The resistant genotypes released to farmers in Brazil were developed from the existing cultivars. However, the cultivars of Arabica coffee existing in North Sumatra Province of Indonesia is not yet researched to find resistant genotypes. The goal of this reseach was to determine variability of coffee leaf rust and leaf morphology. In total of 84 genotypes growing in this Province were selected using nested design. Data was analyzed using nested design, correlation, stepwise regression, and hierarchical cluster analysis. This research revealed leaf rust severity had high genotypic variation, low heritability, and high genetic adveance. Ratios of leaf morhology showed moderate to high genotypic variation and heritabilities. Leaf rust severity (y) significantly correlated with both ratio of leaf length with leaf area (x1) and ratio of leaf length with leaf width (x2) with equation y = 2,04 + 62,48x1 3,95x2 with coefficient of multiple correlation R = 0,470**. By using leaf rust severity and these two ratios in cluster analysis, one cluster comprised 18 genotypes with medium leaf rust severity. It could be concluded that resistant genotypes of Arabica coffee might be possible to develop from the existing cultivars. Leaf rust severity might not be used as selection parameter in breeding for leaf rust resistance.


1987 ◽  
Vol 65 (5) ◽  
pp. 949-953 ◽  
Author(s):  
James S. Coleman ◽  
Clive G. Jones ◽  
William H. Smith

The interaction of an acute ozone dose, plant genotype, and leaf ontogeny on the development of cottonwood leaf rust on eastern cottonwood (Populus deltoides Bartr.) was investigated. A rust-resistant (ST 66) and a rust-susceptible (ST 109) clone were exposed to charcoal-filtered air or were fumigated with 393 μg m−3 (0.20 ppm) ozone for 5 h. Forty hours after fumigation, leaf material of different developmental ages was inoculated with urediospores of Melampsora medusae Thum., and uredia production was measured after 10 days. Ozone fumigation of cottonwoods significantly reduced uredia production by M. medusae on both clones and all leaf ages without causing visible leaf injury or measurable changes in cottonwood height growth, leaf production, leaf length, or root/shoot biomass. Uredia production was strongly affected by ozone treatment, cottonwood genotype, and leaf age, but interactions among these three factors did not occur.


Euphytica ◽  
1990 ◽  
Vol 48 (3) ◽  
pp. 211-214 ◽  
Author(s):  
Andrzej Gąsowski

Crop Science ◽  
2006 ◽  
Vol 46 (2) ◽  
pp. 578-588 ◽  
Author(s):  
M. A. Babar ◽  
M. P. Reynolds ◽  
M. van Ginkel ◽  
A. R. Klatt ◽  
W. R. Raun ◽  
...  

2019 ◽  
Vol 37 (2) ◽  
pp. 204-209
Author(s):  
Valter C de Andrade Júnior ◽  
Amanda G Guimarães ◽  
Tiago D Firme ◽  
Aline Aparecida A Costa ◽  
Márcia Regina da Costa ◽  
...  

ABSTRACT Correlations and path analysis between characteristics can aid the selection of important attributes in breeding programs. Thus, the objective of this work was to perform genotypic, phenotypic correlations and path analysis under commercial yield of garlic bulbs, depending on morphological and agronomic variables. The experiment was carried out in 2017 at the Universidade Federal dos Vales do Jequitinhonha e Mucuri and Universidade Federal de Lavras, using ten garlic genotypes, eight trials and two commercial cultivars, Caçador and Jonas. We evaluated: plant height; number of leaves, total bulb number; total bulb mass, total bulb yield, marketable bulb yield and number of cloves per bulb. The genotypic and phenotypic correlations were positive and significant between marketable yield of bulbs with bulb mass, total yield and number of cloves per bulb, indicating that selection based on these characteristics will help increase the yield of garlic. However, only the number of cloves per bulb had a direct effect and a relevant indirect effect on the marketable yield of garlic.


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