The epigenetic induction of variability of morphological and molecular characters of pea (Pisum sativum L.)


Katarína HRUBÍKOVÁ, Milan BEŽO, Henrieta KNOBLOCHOVÁ   (Slovak Agricultural University, Nitra)

Paper is in English
(4 ill., 22 ref)

     An extension of biological variability of the plant genom makes if possible to create new biological materials with modified genetic performance. Such a biological material can be used in a breeding program or in the next research. The epigenetic heredity or the epigenetic control of the genes activity is a sphere of the intense research into molecular biology and genetics. The epigenetic phenomenon analysis extends the theoretical knowledge of hereditz and organism variation and creafes assumptions for using these data in cultivation and breeding of plants. The purpose of the study reported here was to analyze changes in the conditions of an implementation of genetic information in cell depending on the acting time of ultrasound. These changes were assessed on the basis of morphological traits (evaluation of phenotypic variation by description) and molecular characters (analysis of electrophoretic separation of storage proteins). Variation in the morphogenic processes of pea plants was conditioned not only by genetic but also by epigenetic factors (ultrasound). Ultrasound breaks intercellular interactions due to its self-cleavage effect, thus enabling to stimulate separation of meristematic cells, which resulted in multiple sheet formation. The polymorphism analysis of pea storage proteins indicated that the action of ultrasound has the breaking effect on the protein structure

Key words: epigenetic factors, ultrasound, electrophoresis of storage proteins, pea
AGROVOC descriptors: pisum sativum; induced mutation; morphogenesis; biological development ; biological properties; storage proteins; electrophoresis; ultrasonics

Adress: Ing. Katarína Hrubíková, PhD., Dept. of Plant Physiology, Fac. of Agronomy, Slovak Agricultural University in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, tel. +421-87-6508 454, e-mail:hrubikov@afnet.uniag.sk
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Studies on the embryology of the grasshoper Chrotogonus lugubris Blanchard (Orthoptera, Acridoidea, Pyrgomorphidae). III. Organogeny


Khaled Mohamed Abdel RAHMAN   (Entomol. Dept., Fac. Sci., Cairo University, Egypt)

Paper is in English
(14 ill., 30 ref.)

     Organogeny of Chrotogonus lugubnis Blanchard (Orthoptera) was studied. The alimentary canal was formed by ectodermal invaginations representing the stomodaeal (21.25%D) and proctodaeal (23.21%D) invaginations. During development, their ends came to impinge each upon a mesodermal mass representing the mesenteron rudiments which became better defined in stage 61.87%D. Malpighian tubes appeared by stage 58.8 as six ectodermal outgrowths from the prctodaeal invagiation. The salivary glands arose as a pair of ectodermal invagiations at the base of the labium rear the developing hypopharynx in stage 59.68%D. Neuroblasts appeared in stage 23.21%D and formed two lateral strands. They gave rise to the ganglionic cells, and later, the commissures and connectives appeared. Neurobtasts were then degenerated and disappeared through stages 61.87-70.33%D. The cardioblasts appeared in stage 36.01%D, forming two lateral strands from the labial to the tenth abdominal segment. The heart was formed by stage 59.68%D as these strands were pushed upward by the dorsal growth of the somatic mesoderm forming a tube represents the hearth. The aorta developed from the walls of the antennal coelomic sacs. The tracheal system developed by ectodermal invaginations in stage 36.01%D. The reproductive organs developed from the genital cells in stage 36.01%D. They gave rise to a gonad rudiment on each side of the embryo

Key words: embryogenesis, grasshoppers, Acrididae, locusts
AGROVOC descriptors: Acrididae; embryonic development; organogenesis

Adress: Khaled M. Abdel Rahman, Fac. Sci., Entomol. Dept., Cairo University, Cairo, Egypt
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Occurence and life history of Lixus subtilis Boheman (Coleoptera: Curculionidae) developing on Amaranthus retroflexus L. and Amaranthus caudatus L. in Slovakia


Monika VRÁBLOVÁ, Peter TÓTH, Ľudovít CAGÁŇ   (Slovak Agricultural University, Nitra)

Paper is in English
(2 tab., 32 ref.)

    In the period 1995 to 1998, field surveys were corducted to determire the incidence of curculionid beetles associated with Amaranthus retroflexus L in Slovakia. Of the 24 species collected, Lixus subtilis Boheman was found to occur regularly at most of localities. This species was usual in the warmest regions in the south of Slovakia, but it was not available in the central and northern parts of Slovakia where climate is cold. L. subtilis was not detected in sugar beet plants and this insect did not damage sugar beet at the locality Nitra-Malanta in south-western Slovakia. At this locality, L. subtilis did a regular damage to weed A. retroflexus plants and cultivated Amaranthus caudatus L. L. subtilis started egg laying in the first week of June and most of the larvae developed in the stem from mid-June until the end of July. Larvae bored through the stem tissue towards the apical end of the plant. Pupation continued inside the stem from the beginning of August. The first L. subtilis adults developing on A. retroflexus plants emerged in the second half of August. Newly emerged adults made an oval exit hole, through which they left the stem. Total preimaginal stage of the weevil lasted roughly two months and a half. Parasitization of the weevil larvae by Scambus detritus (Holmgren) (Ichneumonidae) was more than 50%.

Key words: Amaranthus spp., Lixus subtilis, biological control, weeds, Curculionidae
AGROVOC descriptors: Lixus; Amaranthus; insect nematodes; natural enemies; insect control ; pests; Slovak Republic

Adress: Ing. Monika Vráblová, Katedra trvalo udržateľného rozvoja, Fakulta záhradníctva a krajinného inžinierstva, Slovenská poľnohospodárska univerzita v Nitre, Mariánska 10, 949 01 Nitra, tel. +421-87-6526 637, e-mail:vrablova@sai.uniag.sk
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Syrphidocoenoses (Sirphidae, Diptera) of some non-crop habitats of Nitra District


Adriana KRÁLIKOVÁ, Alena RAKOVSKÁ, Jaroslav NOSKOVIČ   (Slovak Agricultural University, Nitra)

Paper is in Slovak
(4 tab., 1 ill., 31 ref.)

    The paper presents the results of the research on hovenflies in the 11 habitat types situated in 44 localities around agrocoenoses of Nitra District. During research 581 hoverly individuals belonging to 28 species were obtained by individual catching and sweeping. Out of them 16 species belong to a trophic group of aphidophagous. Episurphus balteatus (De Geer, 1776) and Melanostoma mellinum L.(1758) were the most distributed ones from this group. These species have the highest values of constancy and repeated high eudominant and dominant abundance in the followirg habitats: dammed lakes with phragmites and typha plants, oak-hornbeam woods, oak-cerri woods and Robinia pseudoacacia plantations. These habitats can serve as possible refuges of the occurence of E. balteatus and M. mellinum. They can spread from these habitats info surrounding agrocoenoses and affect there as biocontrolling agents of aphid and pollinators

Key words: hoverflies, habitat types, constance, dominance, Nitra Distric
AGROVOC descriptors: Syrphidae; habitats; biotopes; Slovak Republic

Adress: RNDr. Adriana Kláliková, CSc., Katedra ochrany životného prostredia a zoológie, Agronomická fakulta, Slovenská poľnohospodárska univerzita v Nitre, Tr. A. Hlinku 2, 949 76 Nitra, e-mail:kralikov@uniag.sk
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Weight variability of a root system of some grasses and an assortment of tall fescue (Festuca arundinacea Schreb)


Norbert GÁBORČÍK, Jana MARTINCOVÁ, Ľubomír GONDA   (Vyskumny ustav travnych porastov a horskeho poľnohospodárstva, Banská Bystrica)

Paper is in Slovak
(2 tab., 1 ill., 14 ref.)

     Two pot experiments were carried out to study a variability of root system and some traits (number of roots, root volume) of four grass species including 11 cultivars of tall fescue (Festuca arundinacea Schreb). In experiment 2, root weight and a chloropohyll concentration a+b in leaves of 50 tall fescue cultivars was investigated. Cocks foot (Dactylis glomerata L.) was characteriyed as the species with the smallest root weight and annual ryegrass (Lolium multiflorum Lam.) as that with the highest root weight, which corresponds to a narrower root : shoot ratio (R:S). In the case of tall fescue and perrenial ryegrass (Lolium perenne L), this value was close to 1.00. There was a great variabitity of root weight in both of the studied assortments of tall fescue cultivars. In experiment 1, the root weight varied between 0.208 and 0.643 g per plant and in experiment 2 from 0.211 to 0.560 g per plant. The cultivars, both with high and low root weight, may produce a different shoot weight. The different system of assimilate disttibution between shoot and root system may be related to cultivars persistence. A strong correlation (r=0.7206+) was found between root weight and chlorophyll concentrations a+b in leaves of tall fescue

Key words: grasses, tall fescue, Festuca arundinacea, cultivars, chlorophyll, root
AGROVOC descriptors: Festuca arundinacea; varieties; roots; root systems; length; weight

Adress: doc. Ing. Norbert Gáborčík, CSc., Výskumný ústav trávnych porastov a horského poľnohospodárstva, Mládežnícka 36, 974 21 Banská Bystrica, fax: +421-88-73 25 44
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