Genotypic and phenotypic correlations among coffee leaf rust symptoms of Arabica coffee genotypes in North Sumatra. Indonesia

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.

Character Association and Path Coefficient Analysis of Certain Biometrical Traits among Fenugreek Genotypes under Different Environmental Conditions

Background: Fenugreek is grown under various agro-climatic conditions of the world as well as in India. However, overall yield and quality depends upon various quantitative characters that exist during crop growth period. Therefore, this study aimed to find out the character association and path coefficient analysis among the seed yield and yield contributing characters in fenugreek genotype. Methods: Thirty genotypes were sown with three replications under two environments namely normal (E1) and limited (E2) irrigation conditions during Rabi season 2019-20. The experiment was laid down in RBD. Result: The genotypic and phenotypic correlations were exhibited significantly positive for number of pods per plant (0.765, 0.725 and 0.670, 0.651), number of seeds per pod (0.705, 0.650 and 0.666, 0.640) and pod length (0.376, 0.348 and 0.351, 0.327) with seed yield per plant in both the environments i.e. E1 and E2. The highest direct effect on seed yield per plant was observed for number of pods per plant (0.693, 0.602 and 1.030, 0.754), number of seed per pod (0.396, 0.378 and 0.490, 0.421) and test weight (0.338, 0.304 and 0.405, 0.368) at genotypic and phenotypic levels in both environments i.e. E1 and E2.

Genetic Parameters of Stem and Wood Traits in Full-Sib Silver Birch Families

This study investigated heritability of stem and wood traits to improve Swedish silver birch (Betula pendula Roth.) through breeding. Birch is 12% of Sweden’s forest area but mainly used for low value pulp or firewood. This paper applied non-destructive test (NDT) methods, and estimated traits’ heritability (h2), to help breed birch for high value solid wood products. Two trials of 22 families were assessed at age 19 for stem diameter (DBH), stem straightness, rough brown bark height (BH), grain angle (GA), Pilodyn penetration depth (Pilo) and acoustic velocity (AV). X-ray densitometry was performed on a subsample of radial cores taken at 1.3 m from the ground to get an average benchmark density. The h2 values were moderate for GA (0.20 and 0.21) and Pilo (0.53 and 0.48) at the two sites, but the h2 values for AV were low (0.05 and 0.30). There were moderate genotypic correlations between BH and DBH (0.51–0.54). There were low genotypic and phenotypic correlations between NDT measurements and other traits so including NDT in birch breeding efforts should not inadvertently reduce size, stem or wood quality. The high genetic correlations between sites suggest that GA, Pilo and AV values were determined more by genotype than by environment.

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

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

THE EVALUATION OF YIELD AND AGRONOMIC TRAITS OF FLAX GENOTYPES UNDER LATVIAN CONDITIONS

This study aim was evaluated of flax genotypes regarding productivity, resistance to lodging and diseases as well as yield dependence relationships among phenotypic and quality traits. The 14 fibre flax genotypes were evaluated in field conditions on the background of natural infection from 2014 to 2018 for agronomically important traits and from 2015 to 2018 for occurrence diseases of flax. The data were recorded for the 15 following agronomic traits, such days to flowering, days to early yellow ripening stage, total plant height, technical height, stem yield, fibre content, 1000 seed weight, vessels per plant, harvest index, seed yield, oil content, resistance to lodging and fungal diseases during early yellow ripening stage. Genotypic and phenotypic correlations between yield and yield components were identified that total plant height, technical height and days to early yellow ripening stage played a major role on stem yield as well vessels per plant and harvest index on seed yield. The flax genotypes ‘Vilani’, ‘L26-1’, ‘K9-1’, ‘T36-1’, ‘S37-1’ exhibited significant highest stem yield ranging from 643.20 to 693.32 g m-2 and technical length ranging from 65.90 to 70.58 cm comparing to standard variety ‘Vega 2’. The most perspective genotype of ‘Vilani’ with quit low susceptibility to anthracnose, pasmo and powdery mildew and resistance to lodging was identified.

Associations between morphological and agronomic characteristics in garlic crop

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.

Interaction of Eggplant Genotypes by Cropping Systems and Correlations between Characters

The eggplant, Solanum melongena L. is a crop that is in the expansion phase, mainly due to the medicinal properties of its fruits in lowering cholesterol levels and blood pressure. The objective of this work was to evaluate eggplant genotypes in different cropping systems, identifying those most adapted to the Meso-region of Atlantic Forest. The experiment was conducted between December 2011 and May 2012, in the experimental area of the Department of Agronomy of the Federal Rural University of Pernambuco - UFRPE, Recife, PE, and at the Experimental Station Luiz Jorge da Gama Wanderley - IPA in Vitória de Santo Antão, PE, located in the Meso-region of Atlantic Forest. We assessed two open-pollinated cultivars and six eggplant hybrids in three cultivation systems: conventional, organic and hydroponic. A randomized complete block design with eight treatments and six replicates was used in each of the three systems. The hydroponic cultivation system exhibited the best results in all the genotypes in the studied variables, in which five hybrids presented better performance in this system. The hybrid of Ciça and Embu, open pollinated cultivar, showed no significant difference between the systems. The hybrids Comprida, Chica and Blanca showed higher commercial fruit yield in all cultivation systems. The hydroponic system presented that the majority of the genotypic and phenotypic correlations smaller than those of the conventional and organic systems.

Genetic control of silvicultural traits in Balfourodendron riedelianum (ENGL.) ENGL.

The Atlantic Forest has very high levels of biodiversity and is considered one of the most important and threatened biomes in the world. Balfourodendron riedelianum is one of the forest’s characteristic tree species that is currently under considered endangered due to timber extraction and forest fragmentation. With the goal of generating information that may contribute to the genetic conservation of B. riedelianum, genetic parameters are estimated for quantitative traits important for silviculture in a provenance and progeny test located in the Experimental Station of Luiz Antônio, São Paulo State, Brazil. The test was established in 1986 and consists of three provenances, from which open-pollinated seeds from 19 seed trees were collected. The following traits were evaluated at 32 years of age: diameter at breast height (DBH), total height (H), stem height (SH), stem straightness (SS), and forking (FOR). The estimates were carried out using the REML/BLUP method. Significant genetic variation among progenies was detected for all traits (except SH) and between provenances for DBH. The coefficient of individual genetic variation (CVgi) ranged from 2.5 to 9.5 %. The mean heritability among progeny ( $h_f^2$ ) was substantial for DBH (0.44) and FOR (0.36), enabling the selection of families with the highest DBH and lowest FOR for population improvement. Genotypic and phenotypic correlations among traits were also found. We conclude that there is genetic variability in the population that can be exploited in future breeding programs and for the genetic conservation of the species.