Însuşirile morfobiologice şi agrochimice la liniile de perspectivă de tomate

The article presents the results of the evaluationof some tomato perspective lines developedat the Institute of Genetics, Plant Physiology and Plant Protection, Republic of Moldova. Testing on the basis of productivity, resistance to alternariosis and morphobiological characteristics of the fruit, and subsequent clusterian analysis, showed that the lines separated into three clusters differ on the basis of the fruit weight, fruit length, fruit diameter, mesocarp thickness, pericarp thickness, seminal lojes. Lineswith increased productivity –L 304, L 306, L 309 and L 310 have been identified that can be included in the breeding programs. Lines L 304, L 306, L 308, L 310 exhibited a reduced degree and frequency of attack of alternarias and may be recommended as a source of resistance to disease

Efecte genice implicate în manifestarea unor caractere cantitative la tomate

n the article are presented the results ofthe research onthe genetic effects involved in the manifestation of some quantitative characters to tomatoes. It has been established that the various actions (aditive -a, dominant -d) and epistatic interactions (aa, ad, dd) of the genes vary in their degree and orientation (+/-), and depend on the combination, traits and participate to the inheritance of morphobiological and agronomic traits of tomatoes. Duplicate epistasis play an important role in forming the phenotype of these characters in most combinations. As a result of the clustering analysis of the degree of association of the characters mean in the F2 population with the investigated gene effects, it was found that in all cases, the F2media displayed a high associative association with epistasis ad. The broad spectrum of gene effects involved in the formation of the phenotype of morphobiological and agronomic features highlights their genetic basis which considerably contributes to the targereof tomato breeding

Reacţia unor linii de perspectivă de tomate la fungii Alternaria alternata şi Fusarium spp.

Abstract. Experimental data concerning the reaction of some tomato lines created at the Institute of Genetics, Physiology and Plant Protection (Republic of Moldova) to the fungal pathogens Alternaria alternata, Fusarium oxysporum and Fusarium gibbosum are presented in this paper. The treatment of the seeds with fungal culture filtrates obtained by inoculation of fungal mycelium in a Czapek-Dox medium led to different reactions of tomato genotypes at early stages of ontogenesis, with stimulating or inhibiting effects being observed on the germination processes and on the growth of embryonic root and stem. By factorial analysis of variance, it was found that the largest contribution in the source of variation of the embryonic root and stem length had the fungus species, its contribution constituting 73.9 and 66.9%, respectively. The genotype also had an important role, especially for stem length. The genotypes that were poorly affected by fungal pathogens in laboratory and field conditions were identified. Rezumat. În lucrare sunt prezentate date privind reacţia unor linii de tomate, create în Institutul de Genetică, Fiziologie şi Protecţie a Plantelor, la fungii patogeni Alternaria alternata, Fusarium oxysporum şi Fusarium gibbosum. Tratarea seminţelor cu filtrate de cultură de fungi, obtinute prin inocularea miceliului fungic în mediul Czapek-Dox, a condus la reacţii diferite din partea genotipurilor de tomate la etapa timpurie a ontogenezei, fiind înregistrate efecte de stimulare sau efecte de înhibare a proceselor de germinaţie şi de creştere a rădăciniţei embrionare şi tulpiniţei. Prin analiza bifactorială a varianţei s-a constatat că cea mai mare contribuţie în sursa de variaţie a lungimii rădăciniţei embrionare şi tulpiniţei a avut-o specia de fungi, aportul acestuia constituind 73,9 şi 66,9%, respectiv. Un rol important l-a avut şi genotipul, îndeosebi pentru lungimea tulpiniţei. În condiţii de laborator şi camp au fost identificate genotipurile slab afectate de patogenii fungici

Studii privind caracterele morfobiologice, productivitatea şi rezistenţa la temperaturi înalte la tomate

The paper presents the results of the appreciation of varieties and lines from the collection of tomatoes of the Institute of Genetics, Plant Physiology and Plant Protection, Republic of Moldova based on productivity, resistance to stressing temperatures and some fruit characters. The analysis of the useful characters of the studied forms from the collection revealed a wide variability in the fruit characters, the overall productivity, the share of the fruits, which allows selection and recommendation of the most valuable forms for hybridization and obtaining new varieties and hybrids of different destination. Cluster analysis (k-means method) demonstrated that the 38°C temperature level manifested a higher discriminative capacity of tomato clusters based on root and strain length (controlled conditions), which revealed the more pronounced interaction specificity with this temperature level. Were identified clusters of tomato genotypes with diminished reaction at stressful temperatures, which is important for the involvement in programs to improve genotypes with increased resistance to heat