Emergence rate of seedlings from hard okra seed coats and seedling growth of some genotypes of West African okra (Abelmoschus caillei)

P P.M. Jonah1, G.K. Farauta3, Y. M. Kwaga1, H.E. Shehu1, N.M. Fakuta4, B.P. Mshelmbula2

1Department of Crop Science, Adamawa State University, Mubi, Nigeria
2Department of Botany, Federal University, Lafia, Nassarawa State, Nigeria
3Department of Agricultural Technology, Faculty of Education, Adamawa State University, Mubi, Nigeria
4Rubber Research Institute of Nigeria, Gum Arabic Sub-station, Gashua, Nigeria

(Manuscript received 12 March 2019; accepted for publication 30 April 2019)

Abstract. In 2017 and 2018 cropping season, field experiment was conducted at the Food and Agricultural Organization and Tree Crop Plantation, Department of Crop Science, Adamawa State University, Mubi using fifteen genotypes of West African okra. The study was undertaken to study the emergence rate of seedlings from hard okra seed coats, seedling growth and their development. The seeds of the genotypes were soaked in NaCl solution for 24 hours to accelerate the breaking of seed dormancy and to ease seed germination. Tough seed coat usually impairs seed germination by establishing a permeability barrier which can interrupt water uptake required for imbibition, radicle and seedling emergence. The combined analysis results revealed a highly significant (P≤0.01) difference among these genotypes with respect to days to first and 50% flowering including days to first harvest. Furthermore, accession 3 (NG/SA/DEC/07/0448) and accession 11 (Yar kwadon) flowered earlier, had shortest days to first harvest, recorded the highest number of seedlings and emergence percentage than the other genotypes studied.

 

Races of bacterial spot pathogen infecting genus Capsicum in Bulgaria

K. Vasileva1, N. Bogatzevska2

1Maritsa Vegetable Crops Research Institute, 32 Brezovsko Shosse Str., 4003 Plovdiv, Bulgaria
2Institute of Soil Science, Agrotechnologies and Plant Protection “N. Pushkarov”, 7 Shosse Bankya Str., 1331 Sofia, Bulgaria.

(Manuscript received 27 February 2018; accepted for publication 21 April 2019)

Abstract. The causative agents of bacterial spot disease infecting pepper are the species X. euvesicatoria and X. vesicatoria common in the typical pepper growing areas (Northern: Black Sea Costal and Central; Southwest; Southern – Upper Thracian valley) in Bulgaria. The pathogens refer to pepper P pathotype (22 strains) and pepper-tomato РТ pathotype (52 strains). The natural population of X. еuvesicatoria is heterogeneous of pathotype and physiological races. Widespread is race P6 in the P of the pathogen, followed by race P1. Single strains are assigned to P3, P9 and P10. In PT, races P0, P1, P4, P5 are differentiated, the dominant race in PT is the P4 race in combination with the tomato race T2. For the first time in Bulgaria in the natural population of X. vesicatoria, are detected strains which infect only pepper, differentiated are races Р0, Р2 and Р3. The population of X. vesicatoria PT prevails in private gardens and vegetable areas near tomatoes. Differentiated races are P1, P3 and P4 in combination with tomato races T1, T2 and T3. Race P3 occurs in P and PT pathotype.

Variation and stability of the advanced bread wheat (Triticum aestivum L.) genotypes under various environment conditions in Trakia region

İ. Öztürk1*, T. Kahraman1, R. Avcı1, A. Şen2, T.H. Kılıç1

1Trakia Agricultural Research Institute, Edirne, Turkey
2Department of Biology, Faculty of Science, İstanbul University, İstanbul, Turkey

(Manuscript received 10 October 2018; accepted for publication 24 January 2019)

Abstract. Various environmental conditions can cause some biotic and abiotic stress factors and reduce yield and quality of wheat. This research was carried out to determine the effect of the environmental conditions on yield, some agronomic, and leaf rust disease of the bread wheat genotypes in four different locations in Trakia region, Turkey. The experiment was established with 25 genotypes in randomised complete block design (RCBD) with 4 replications in 2008-2009 cycles. Grain yield, days to heading and maturity, plant height, lodging resistance, leaf rust and relationship among characters were investigated. The temperature and rainfall were scored at GS24-33, GS34-43, GS45-75 and GS77-89 growth stages and compared with the investigated traits. According to the results, significant differences among locations and some investigated parameters were found based on rainfall and temperature with yield and other investigated traits. The mean yield of the genotypes was 5851 kg ha-1, and CMSW97WM518S-12 had the highest yield with 6601 kg ha-1. Tekirdağ was the highest yielding location with 7022 kg ha-1, followed by Edirne (5808 kg ha-1) and Kırklareli (5754 kg ha-1). Due to various environment conditions infection of the leaf rust varied and there were differences among locations. Cultivar Aldane and three lines were resistant to leaf rust. Positive relation between yield with plant height and lodging resistance was found and this means that genotypes which have tall plant had higher yield potential. Rainfall at GS24-33 (r= 0.855) and GS34-43 (r= 0.911*) had a significant and positive effect on grain yield. Increase of temperature during the shooting, heading and grain filling period decreased grain yield, so negative association between grain yield and temperature at GS34-43 (r= -0.761), GS45-75 (r= -0.635) and GS77-89 (r= -0.815) was found. The overall evaluation suggested that increase of temperature from shooting up to grain filling decreased the grain yield duration of the maturating stage. Rainfall during the vegetative growth phase increased grain yield and biomass of plant of genotypes.

Correlations between some economic larval traits of silkworm

  1. Gündüz, Ü. Şahan

Department of Animal Science, Faculty of Agriculture, Uludag University, 16059 Gorukle, Bursa, Turkey

(Manuscript received 25 August 2018; accepted for publication 18 December 2018)

Abstract. Silkworm, Bombyx mori L. is an economic insect that has great importance on cocoon and silk production. The development of sericultural industry depends on quality and yield in terms of qualitative and quantitative silkworm characters. Mature larval weight and silk gland mass are important factors in silkworm breeding. Silk gland mass has significant impact on the synthesis of silk protein in fifth larval stage. The investigation was conducted to evaluate the correlations between silk gland mass and mature larva weight of M and ZF (China), and N and ZB (Japan) lines and their hybrids MxN, ZFxZB. In this research, silkworm lines and hybrids were reared at the laboratory with 600 silkworm larvae for each four lines and their hybrids to determine these silkworm traits. Analysis of variance indicated that the mean values in Chinese lines and hybrids were found to be significant (P<0.01) for mature larva weight. On the other hand, mean value of silk gland mass was determined as important for Chinese, Japanese lines and hybrids (P<0.01). Both mature larva weight and silk gland mass have positive correlation in Chinese lines (r=0.659) and hybrids (r=0.643) (P<0.01). Otherwise, the correlation between these characters were not found to be significant for Japanese lines. As a result, it is necessary to search the correlation between different characters and to protect the genetic diversity in silkworm lines.

 

Genetic interrelationship among quantitative traits and path analysis of some West African okra (Abelmoschus caillei) genotypes

P.M. Jonah, Y.M. Kwaga

Department of Crop Science, Adamawa State University, PMB 25, Mubi, Nigeria

(Manuscript received 5 July 2018; accepted for publication 30 November 2018)

Abstract. Thirty-six entries of a half diallel cross were evaluated at the Teaching and Research Farm, Adamawa State University, Mubi in 2012 and 2013 under rain fed conditions. The investigation was conducted to study inter-character correlations and path coefficient analyses of yield related traits in West African okra. Fresh pod yield exhibited highly significant (P≤0.01) positive correlation with pods/plant, pod length, branches/plant, pod diameter and leaves/plant. Pod length recorded a highly significant positive correlation with plant height, pod diameter, number of leaves/plant, branches/plant and pods/plant. Similarly, pod diameter had a highly significant positive correlation with plant height, number of leaves, branches and pods/plant. Furthermore, number of pods/plant and branches/plant recorded highly significant positive correlation among yield related traits except plant height. The path coefficient analysis of fresh pod yield and yield related traits showed that number of pods/plant gave the highest direct contribution and percentage yield contribution of 47.83%, followed by pod diameter which contributed 4.58%. Also the highest combined contribution of 14.43% came from pods/plant and pod diameter. Residual percentage contribution was 30.64% revealing that pod yield attributes in this study explained 69.36%. This investigation suggests that pods/plant and pod diameter can be considered as selection criteria for the improvement of West African okra genotypes.

Genetic diversity at four Nigerian sheep breeds assessed by variation of albumin and carbonic anhydrase in cellulose acetate electrophoretic systems

O.H. Osaiyuwu1*, M.O. Akinyemi1, A.E. Salako1, O.K. Awobajo2

1Animal Breeding and Genetics unit, Department of Animal Science, University of Ibadan, Ibadan, Nigeria
2Department of Agricultural Science Education, Tai Solarin University of Education, P.M.B. 2118, Ijebu-Ode, Ogun State, Nigeria

(Manuscript received 8 May 2018; accepted for publication 3 September 2018)

Abstract. The aim of the study was to evaluate the occurrence and distribution of variations in blood protein markers in sheep breeds in Nigeria and to evaluate the relationships that exist among them. A total of 100 sheep comprising of twenty-five each of Balami, Uda, Yankassa and West African Dwarf (WAD) breeds were sampled for biochemical studies. Blood was collected to determine variations at the Albumin and Carbonic Anhydrase (CA) structural protein loci using cellulose acetate electrophoresis. All tested loci were polymorphic yielding four allelic variants (CAF, CAS, AlbA, and AlbB) at the two protein loci. Genetic variability in the studied population was accessed using heterozygosity (observed – Ho and expected – He), effective number of alleles (Ne), fixation index (F) and gene flow (Nm). Genotypic frequencies ranged from 0.01 to 0.62 for CA and 0.25 to 0.49 for Alb loci. Estimated heterozygosity values ranged from 0.32±0.28 at Balami sheep to 0.70±0.22 in WAD with a global average estimated at 0.43±0.09 for all the breeds studied. The gene flow values for each of the loci studied were 0.82 and 1.24 for Alb and CA, respectively, with an average value of 1.03. The results showed that Yankassa and Balami sheep populations are more genetically (Nei’s genetic identify value – 0.99) alike compared to Yankassa and WAD (0.73). Based on the values of heterozygosity (mean He =0.70 and Ho =0.45) assessed by variation of albumin and carbonic anhydrase the most genetic diverse is WAD sheep breed among the studied populations.

Study on the continuity of farmer`s breeding activity with Patch Faced Maritza sheep breed

P. Zhelyazkova*, V. Petrova, D. Dimov

Department of Animal Sciences, Agricultural University, 4000 Plovdiv, Bulgaria (Manuscript received 4 June 2018; accepted for publication 2 October 2018)

Abstract. The aim of this study was to analyze tendencies in the population of Patch Faced Maritza sheep breed and estimation of sustainability of the breeding program for this breed by analyzing continuity of farmer`s breeding activity. Patch Faced Maritza sheep breed is a local Bulgarian sheep breed typical for lowland regions of South Bulgaria and could be successfully used as local genetic resource in productive strategies for milk and meat production. Data about breeders and population structure of the breed during 27 years (1991-2017) were provided by the breeding association of Maritza sheep breed. The changes in the population structure during the 2005-2017 were tracking. The number of breeders included in the breeding program was increased from 10 to 88 herds. This positive trend in the population and increased farmer`s interest to participate in the breeding program were due to government programs for supporting sheep farming and preserve many indigenous sheep breeds that are part of agricultural heritage. The increased number of herds included in the breeding program led up to enlarge active population in three main reproductive categories: ewes, rams and breeding lambs. Comparatively small number of ewes, rams and breeding lambs which in 2005 were respectively 375, 13 and 180 run to 7678, 493 and 1868 in 2017. This enlarge of active population was achieved by three ways: joining farmers which kept Patch Faced Maritza sheep but not participating in official breeding program of the breed, increasing the breeding lambs for replacement rate and limited upgrade crossing. On the based breeding activity contracts with farmers it was estimated continuity of breeding activity in two categories of breeders: finished breeding activity with the breed and continuing with active breeding activity with the breed. The causes for discontinuing of active farmers breeding work were analysed. A total number of farmers which finished breeding activity was 54 for 27 years. Averaged continuity of farmer`s breeding activity was 4.26 years. The analysis of this information find out five reasons for discontinuing farmers breeding activity: disinterest, death, old age, switching to another business, and changing the breed. From the listed reasons the most important are switching to another business 23 farmers and disinterest for active breeding work 17 farmers. The most important fact results nowadays is the fact that Patch Faced Maritza sheep is occurred already in 11 regions in Bulgaria, although 74.11% of the population is situated in two regions Plovdiv and Pazardzhik.

Evaluation of powdery mildew resistance in various melon (Cucumis melo L.) genotypes

Zh. Ivanova*, K. Vasileva, N. Velkov, S. Grozeva

Maritsa Vegetable Crops Research Institute, 32 Brezovsko Shosse Str., 4003 Plovdiv, Bulgaria (Manuscript received 21 August 2018; accepted for publication 14 October 2018)

Abstract. Powdery mildew, caused by Podosphaera xanthii and Golovinomyces cichoracearum, is an economically important disease in melon worldwide. Genetic resistance is one of the most suitable strategies to control powdery mildew. During the last few years several races of the pathogens have been reported. The need to develop resistant varieties is a challenge for each breeding program. Leaf disc assay was used in phytopathology and breeding programs as a rapid and reliable method for evaluation of disease resistance in a large number of plant materials. The purpose of this study was to establish species and races of powdery mildew in Plovdiv region, South Central Bulgaria; to develop a suitable system of pathogen isolation and cultivation; to determine the resistance levels in different melon genotypes available in Maritsa Vegetable Crops Research Institute (MVCRI) – Plovdiv collection by the leaf disc assay. Fifty-three melon genotypes, including lines, varieties, hybrids and ten differential lines were tested. The data showed that causal agent of powdery mildew was race 1 of P. xanthii in Plovdiv region. Our experimental results indicated that for the long-term storage of powdery mildew it is preferable to keep a whole plant under in vitro conditions. This allows the preservation of powdery mildew for two months before transferring on a new tissue. Thirty-four of the tested melon genotypes reacted as immune or resistant and nineteen as susceptible. Resistant melon genotypes are a suitable source in initiating a new breeding program aimed to increase resistance to powdery mildew.

Knezha 461 – A new maize hybrid from the middle early group

N. Petrovska*, V. Valkova

Maize Research Institute, 5835 Knezha, Bulgaria
(Manuscript received 14 May 2018; accepted for publication 14 September 2018)

Abstract. The article presents the biological and morphological parameters of the new grain maize hybrid from middle early group. The hybrid is acknowledged in 2017, after three years of testing in the territorial station at Executive Agency of Variety Testing, Field Inspection and Seed Control (EAVTFISC) with standard American hybrid P 9494 and Knezha 435, a widespread Bulgarian hybrid. During the period of testing under conditions without irrigation in the experimental field of the Maize Research Institute – town of Knezha the three years average of the new hybrid exceeded the standard P 9494 by 7.4%, and Knezha 435 by 8.6%. In the ecological network of the country in 2011, under conditions without irrigation, the hybrid produced grain yield 2.6% above the foreign and 4.7% above the Bulgarian standard. In 2016 at EAVTFISC the Knezha 461 maize hybrid exceeded by average grain yield the P9494 standard by 1.5%. The testing was conducted at four points under non-irrigated conditions. The moisture content in the harvesting time is near to that of P9494 and lower than the moisture of Knezha 435. The new high-yielding and competitive hybrid Knezha 461 supplies deficiencies in the middle early group of Bulgarian hybrids, where the foreign ones take prevalence.

Variability and grain yield potential of maize (Zea mays L.) genotypes under irrigated condition in central Sudan

M.B. Alhussein1, S.H. Suliman2, A.A. Mohammed3

 

1Maize research program, Agricultural Research Corporation, Wad Medani, Sudan

2Crop sciences section, Faculty of Agricultural Sciences, University of Gezira, Wad Medani, Sudan

3Maize research program, Agricultural Research Corporation, Wad Medani, Sudan

 

DOI: 10.15547/ast.2018.03.038

(Manuscript received 25 May 2018; accepted for publication 27 August 2018)

 

Abstract. These experiments were conducted in two different sites to study the genetic variability and the mean performance of the elite different origin maize genotypes under irrigated condition in central region of Sudan during rainy season of 2015. The experiments were arranged in randomized complete block design with three replicates, the data were collected on days to 50% tasseling and silking, plant and ear height, ear length and diameter and grain yield. The analysis of variance for each site and cross sites showed a significant variability among tested genotypes for grain yield, days to 50% tasseling and silking, plant and ear height, ear length and diameter. Also significant differences were observed for genotypes, site and a cross site for most of the studied traits such as for grain yield, days to 50% tasseling and silking, plant and ear height, ear length and diameter. The combined results for genotypic coefficients of variability and broad sense heritability estimates grain yield, ear length and ear diameter varied significantly among the tested genotypes.