Date of ear emergence: a factor for notable changing the grain yield of modern winter wheat varieties in different environments of Bulgaria

N. Tsenov1*, T. Gubatov1, I. Yanchev2

1 Department of Wheat Breeding and Technology, Agronom Breeding Company, 9300 Dobrich, Bulgaria
2 Department of Plant Science, Faculty of Agronomy, Agricultural University, 4000 Plovdiv, Bulgaria

(Manuscript received 2 November 2020; accepted for publication 15 January 2020)

Abstract. Wheat is a crop with a very long growing season, during which it is subjected to prolonged exposure to many environmental factors. For this reason, the interaction of genotype with conditions is very common for any character of wheat. This study aims to determine whether the grain yield is affected by the change of the ear emergence date (EED) in various environments. In a four-year period, 30 current for national real grain production winter wheat varieties were studied. The EED and grain yield (GY) were studied as quantitative traits within five locations of the country having various soil and climatic conditions. Using several statistical programs, genotype x environment interaction of two traits was analyzed. The emphasis on data analysis was whether changes of traits due to the conditions were related and that the optimization of the ear emergence date could serve as a breeding tool for increasing grain yield. The date of ear emergence and grain yield are traits that are reliably influenced by growing conditions. The change in the date of emergence is mainly of the linear type, while the grain yield shows linear and nonlinear type changes in the same environmental conditions. It was found that the key roles in the change of characteristics are the conditions of the year, with the relatively weakest impact of the genotype on them. There is a positive relationship between the two traits, although their change depends on environmental factors. Although they change to different degrees and in relation to each other, there is a positive correlation between them. The more favorable the environmental conditions, the weaker the relationship between these two traits and vice versa. Under changing climatic conditions, the change in the relationship between the two traits is a signal of the need to create different varieties by date of ear emergence in order to obtain higher yields in the future.

 

Morphological characterization and genetic analysis in bread wheat germplasm: A combined study of heritability, genetic variance, genetic divergence and association of characters

  1. Gerema1*, D. Lule2, F. Lemessa4, T. Mekonnen3

1Bako Agriculture Research Center, Oromia, Ethiopia

2Oromia Agriculture Research Institute, Finfinne, Ethiopia

3Institute of Biotechnology, Addiss Ababa University, Ethiopia

4Department of Horticulture and plant Science, Jimma University, Jimma, Ethiopia

(Manuscript received 20 May 2020; accepted for publication 5 November 2020)

Abstract. The present study was conducted to assess the nature and magnitude of genetic variability and traits association of bread wheat genotypes for yield and related traits. A total of 180 genotypes were evaluated in alpha lattice design with three replications in 2017/18 cropping season. Data for 10 quantitative traits were collected and subjected to analysis of variance. The result from the analysis of variance revealed highly significant variability observed among genotypes for all traits studied. Phenotypic coefficient of variation (PCV) is superior over genotypic coefficient of variation (GCV) for most traits but narrow variations were found between PCV and GCV for most of the traits. Heritability in broad sense and genetic advance as percent of the mean (GA%) were relatively higher for Kernels per spike and grain filling period. Grain yield showed positive and highly significant (p≤0.01) association with number of tillers, kernel per spike and plant height both on genotypic and phenotypic levels.The path coefficient analysis showed that spike length, plant height and kernels per spike had positive direct effect on grain yield on both genotypic and phenotypic levels. Divergence analysis (D2) grouped the total test germplasm into 10 clusters. Among those, clusters IV and IX showed the highest genetic distance and thus the possibility to develop segregating populations upon the crossing of widely related genotypes in those clusters. The results could help researches to utilize the most promising wheat genotypes of this study in future breeding programmes for enhancing desirable traits.

Association between physiological parameters and yield in Triticum aestivum L. genotypes under rainfed conditions

İ. Öztürk

Trakia Agricultural Research Institute, Edirne, Turkey

(Manuscript received 22 July 2019; accepted for publication 6 April 2020)

Abstract. The purpose of the study was to assess the relationships between physiological parameters and grain yield of different bread wheat genotypes. In the present research a total of 25 bread wheat genotypes were tested during the 2016-2017 seasons under rainfed conditions. The experiment was conducted in a randomized complete blocks design with four replications. Grain yield, days of heading, plant height, biomass (NDVI) from GS25 up to GS85 growth stage, chlorophyll content (SPAD) during the heading stage, canopy temperature (CT) at GS60 and GS75 growth stages, and glaucousness were investigated. The results of variance analyses showed that there were significant differences (p<0.01) among genotypes for yield. The mean grain yield was 7948 kg ha-1 and yield ranged from 7033 kg ha-1 to 8759 kg ha-1, the highest grain yield performed by TE6744-16 line. According to the results, significant differences among cultivars in terms of plant height, days of heading, biomass, chlorophyll content, canopy temperature, glaucousness were found. TE6627-6 line had the highest chlorophyll content and also, chlorophyll content positively affected grain yield. Canopy temperature is generally related to yield under drought stress condition in bread wheat. In the study early maturing (days of heading) genotypes had lower canopy temperature. An increase in biomass after the heading phase has positively affected grain yield. In the study, no correlation was found between grain yield and biomass at GS25 and GS45 growth phase. There was a negative correlation between glaucousness with biomass at GS60, GS75 and GS85 growth phase. These results showed that physiological parameters such as biomass (at GS75 and GS85), canopy temperature (at GS60 and GS75), and chlorophyll content (at GS60), and glaucousness could be used for selection parameters under rainfed conditions for yield in bread wheat.

Interrelationships between some vegetative components and fruit quality of Algerian date palm

A. Rekis1,2,3*, Z. Laiadi3

1Department of Agricultural Sciences, Mohamed Khider University, P.O. Box 145, Biskra-07000, Algeria 2Scientific and Technical Research Center on Arid Regions (CRSTRA), University Campus Mohamed Khider, BP 1682 R.P., Biskra-07000, Algeria
3Laboratory of Genetics, Biotechnology and Valorization of Bio-resources, University Mohamed Khider,
P.O. Box 145, Biskra-07000, Algeria

(Manuscript received 28 November 2019; accepted for publication 16 January 2020)

Abstract. The date palm is a monocotyledon thermophilic desert plant, in Algeria grown more than 18 million trees. To have a better quality of dates for the most answered cultivars in Algeria, we can act with fertilization on the palm and these components of the leaflets and spines that affect dates quality. The three cultivars of date palms (Deglet nour-C1, Ghars-C2 and Mechdegla-C3) have been studied to estimate the relationship between leaflet and spine number and date quality. Five phenotypic traits were exploited and subjected to analysis of the principal components in ascending hierarchical classification. The results revealed that the cultivar Deglet nour scored the highest value for the parameters spine number (25) and weight of the date (8.63g), the cultivar Ghars also recorded the highest value for the parameters: number of leaflets (80) and length (4.35cm) and thickness (2.25cm) of the date. In all studied cultivars positive correlations between the length and width of the leaf – on the one side, and weight of the date – on the other, and between the width of leaf and width of the date were found.

Effect of age at first calving on conformation traits in Black-and-White cows

I. Marinov*, Zh. Gergovska

Department of Animal Science – Ruminants and Dairy Farming, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

Abstract. The study included 514 Black-and-White cows from 14 farms of different regions of the country. The cows are on Ist (224), IInd (194) and IIIrd (96) lactation, respectively. A scoring of 24 linear type traits on a scale from 1 to 9 was performed. The average age of first calving (AFC) for all farms included in the study was 880.8 days or 29.4 months. By farms the average age varies from 729.1 to 1266.7 days. A statistically significant effect of age at first calving on the following linear type traits was found: chest width, body depth, rump angle, rump width, fore udder attachment, rear udder height and rear udder width. Between AFC and linear traits stature, chest width, rump angle, rear legs rear view, bone structure, rear udder height, rear udder width and BCS significant negative phenotypic correlations with low to moderate values from -0.12 to -0.27 were reported. Between AFC and the traits fore udder attachment and teat length a significant positive phenotypic correlation of 0.17 and 0.13, respectively, was reported. Cows calved for the first time at an optimal age from 24 to 30 months of age had a wider chest, deeper body, wider rump and rear udder and wider and parallel placed rear legs and thinner and refined bones. The higher age of first calving – over 35 months was not associated with better development of the cows.odbutton6

Correlations between morphological and productive parameters in Burley tobacco

Y. Dyulgerski1, T. Radoukova2*

Abstract. The dependencies are investigated between important morphological and productive signs of Burley tobacco. Five important Burley tobacco varieties – Burley 1000, Burley 1317, Burley 21, Burley 420 and Pliskaare tested. Strong positive correlation between plant height and number of leaves is established. The number of leaves is positively correlated with yield but negatively with the size of the leaves. The size of the leaves is positively correlated with yield and percentage of classes. The length of the vegetative period is positively correlated with all studied morphological parameters and yield, but negatively with the percentage of first class. The increase in yield is related to the percentage of first class. The results obtained can be used successfully to optimize the selection process in Burley tobacco.

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Selection for linear traits for legs and feet and its significance for dairy cattle breeding

I. Marinov

Abstract. Selection based on real problems with the legs and feet – the case of lameness, has low efficiency. Linear type traits describing the structural differences in different body parts including those of the legs and feet can be evaluated directly in a large number of animals at an early stage in the life of cows, by not a large number of specialists. Type traits of legs and feet have low to medium heritability values. There is a genetic relationship both among the various linear foot and leg traits and between them and the issues with animal locomotion. The selection for optimal angle of the foot and the rear leg side view, straight rear legs rear/back view, flat and refined bones and proper locomotion – will result in reduced locomotion problems and diseases of the legs and feet in dairy cows. Negative correlation has been found between problems with legs and feet, milk production and reproductive performance. Problems with legs and feet are one of the causes of premature culling and reduced longevity of dairy cows.

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Investigation on some seed characteristics among sunflower lines and hybrids

M. Drumeva, N. Nenova, E. Penchev

Abstract. Sunflower, being one of the main oil seed crops in the world, is of special economic importance in East Europe. In sunflower breeding the heterosis effect is primarily used. The high yield and the quality properties of seeds depend on the indices of the lines in their pedigree and require the developing of lines with good bio-chemical and technological indices. This investigation involved 5 fertility restorer lines produced by using pollination technique with high gammairradiation doses and subsequent embryo cultivation, 4 cm lines obtained through selfing, and their hybrid combinations. Applying various mathematical models, the correlation between the individual indices (1000 seed weight, percent of kernel, percent of husk, oil content in kernel, oil content in seed and protein content) was demonstrated. The performed analysis revealed negative correlation between the two main quality traits: oil content and protein content. Oil content in kernel correlated insignificantly negatively with the trait 1000 seed weight, while protein content in kernel was in a significant positive correlation with the 1000 seed weight. The established correlations can be directly used at the initial stages of investigation on the breeding materials.

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Estimation of several soil properties by near-infrared reflectance spectroscopy

M.Todorova, S. Atanassova, H. Longer, D. Pavlov

Abstract. There is a great demand for involving rapid, non destructive and less time consuming methods for quick control and prediction of soil quality, environmental monitoring, and other precision measurements in agriculture. Near infrared reflectance spectroscopy(NIRS)is considered as an appropriate alternative method to conventional analytical methods for large scale measurements. The objective of this study was to investigate the possibilities of NIRS for prediction of some chemical properties of soil samples. A total of 97 samples from Stara Zagora, Kazanlak and Gurkovo region taken from the 0-40 cm layer were collected. Soil types were Luvisols, Vertisols, Fluvisols and Rankers. The samples were analyzed for total phosphorus by spectrometric determination of phosphorus soluble in sodium hydrogen carbonate solution, total nitrogen by Kjeldahl method, pH (H O)-potentiometrically and electrical conductivity (EC). 2 The spectral data of all air dried samples were measured using an Perkin Elmer Spectrum One NTS, FT-NIR Spectrometer, within the range from 700 to 2500 nm. Partial Least Squares (PLS) regression was used to built models to determine soil chemical parameters from the NIR spectra. Two-third of the samples were used as a calibration set and the remaining samples as independent validation test set. The best model was obtained for total nitrogen with a coefficient of determination r=0,91, standard error of calibration SEP=336 mg/kg, and the ratio of the standard variation of the reference data to the SEP, indicating the performance of the calibration, of RPD=2,3. The accuracy of prediction was poor for electrical conductivity. The results obtained clearly indicated that NIRS had the potential to predict some soil components rapidly and without sample preparation.

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