Alexandra Matei


THE PRESENTATION OF SILKMOTH BOMBYX MORI L. SP. GENETIC RESOURCES IN ROMANIA AS SOURCE OF INITIAL MATERIAL IN AMELIORATION WORKS

Alexandra Matei, G. Chioveanu, M. Androne, D. Dezmirean, M. Dolis, I. Pasca, M. Bentea

Abstract
The importance of gene bank existence as an essential condition for amelioration programs elaboration is unanimously known for every plant and animal species, from which the permanent preoccupation for its diversification and maintaining by appropriate proceedings of preservation “in situ” or “ex situ”. This way, there is being avoided the loss of biological material, especially of the local races resistant to diseases and adapted to environmental conditions. This study aims the analysis of phenotypic characters variability within the genetic stock of Bombyx mori sp., according to its biological development stages (egg, larva and pupa). Native genetic stock of silkmoth Bombyx mori L. sp. resulted by: identification of local populations gene sources, bilateral exchange of biological material with similar foreign institutes, creation of new genotypes using specific breeding methods. Within its structure, the genetical stock of silkmoth include 72 races. The silkworm specific experimental technique has been applied, differentiated by technological and biological development stages. The sample size that were the base for phenotypic parameters determination as well as the working methods correspond to sericulture technical standards. The main phenotypical and quantitative parameters of the races that represent the gene stock of Bombyx mori sp., have the following values: prolificacy (230-710 eggs/laying), hatchability (80.6-100%), larval stage duration (26-32 days), larvae weight (4.2-5.7 g), larvae pupation rate (80.8-96.6%), raw cocoon weight (1.445-2.361 g), cocoon shell weight (0.240-0.520 g), fiber length (746-1356 m), filament size (2917-3764 m/g). Depending on the quantitative parameters value, the silkworm races are being used differently, entire genetic stock being destined for various technological levels, as follows: 4 active races (parents of hybrids), 3 candidate races for parents of hybrids, 65 races in preservation.

Key words: Bombyx mori, genetic stock, raw cocoon weight, cocoon shell weight, fiber length

PREZENTAREA RESURSELOR GENETICE ALE FLUTURELUI DE MATASE SP. BOMBYX MORI L. ÎN ROMANIA CA SURSA DE MATERIAL INITIAL ÎN LUCRARILE DE AMELIORARE

Alexandra Matei, G. Chioveanu, M. Androne, D. Dezmirean, M. Dolis, I. Pasca, M. Bentea

Rezumat
Importanta existentei unei banci de gene ca o conditie esentiala pentru elaborarea unor programe de ameliorare este unanim recunoscuta pentru toate speciile de plante si animale, de aici preocuparea permanenta pentru diversificarea acesteia, mentinerea prin procedee adecvate de prezervare “in situ” sau “ex situ”. Se evita in acest fel pierderile de material biologic in special a raselor locale rezistente la boli si adaptate conditiilor de mediu. Acest studiu a avut ca scop analiza variabilitatii caracterelor fenotipice in cadrul fondului genetic al speciei Bombyx mori L. in functie de fazele de dezvoltare biologica (ou, larva si pupa). Fondul genetic autohton al fluturelui de matase specia Bombyx mori L., a rezultat in urma: identificarii de surse de gene din populatii locale, schimbului bilateral de material biologic cu institute similare din strainatate; creerii de noi genotipuri utilizand metode specifice de ameliorare. In structura sa fondul genetic al fluturelui de matase cuprinde 72 de rase. S-a aplicat tehnica experimentala specifica viermilor de matase, diferentiata pe etape tehnologice si faze de dezvoltare biologica. Marimea probelor ce au stat la baza determinarii parametrilor fenotipici ca si metodele de lucru au corespuns normelor tehnice sericicole. Principalii parametrii fenotipici si cantitativi ai raselor ce constituie rezerva de gene a speciei Bombyx mori L. se incadreaza in urmatoarele valori: prolificitatea (230-710 nr oua/ponte), ecloziunea (80.6-100%), durata perioadei larvare (26-32 zile), greutatea larvelor (4.2-5.7 g), impuparea larvelor (80.8-96.6%); greutatea gogosii crude 1.445-2.361 g, greutatea incartamentului 0.240-0.520 g, lungimea fibrei 746-1356 m, finetea fibrei 2917-3764 m/g. In functie de valoarea parametrilor cantitativi, rasele fluturelui de matase Bombyx mori L. sunt folosite diferentiat, intregul fond genetic fiind destinat diferitelor nivele tehnologice, astfel: 4 rase active (parinti de hibrizi), 3 rase candidate pentru parinti de hibrizi, 65 rase in conservare.

Cuvinte cheie: Bombyx mori, fond genetic, greutatea gogosii crude, greutatea incartamentului, lungimea fibrei