Nitrogen (N) deficiency causes a morphological disequilibrium between shoots and roots, favoring hypogeal growth. Our hypothesis is that short-term nitrogen deficiency could induce an increase in vine resilience, inducing root growth before the appearance of significant dysfunctions in the epigeal part of the plant. Then, nitrogen availability could be promptly restored through a well-thought-out fertilization plan. In this experiment, two table grape cultivars grafted onto three different rootstocks were studied in three hydroponic growing conditions characterized by different nitrogen availability. After 53 days of treatment, plant morphologies were described, and leaf photosynthetic pigments were quantified. The short-term nitrogen deficiency induced root growth, leading to significantly different proportions among the hypogeal and the epigeal parts, despite no significant differences were recorded concerning shoot growth. Some small differences in the leaf pigmentations indicated an incipient symptom of nitrogen deficiency, and significant differences in the phytomer morphology indicated the possibility of developing low-cost indices for prompt identification of incipient symptoms. This will allow the exploitation of the advantages of short-term nitrogen deficiency while avoiding negative effects on shoot growth by promptly restoring the nitrogen availability.

Aiming to evaluate the in vitro regeneration potential, five varieties of tomatoes (Solanum lycopersicum) were studied for their response in anther culture. Anther explants at an early stage of microspore development were inoculated onto three culture media. The first differentiation processes were recorded during the first three weeks of culture, in darkness. The statistical analysis of the data recorded during the anther culture showed significant differences between genotypes regarding their specific response to culture conditions and the significant influence of the initiation medium composition in triggering the differentiation processes. Under the tested conditions were induced: the embryogenic potential in three genotypes (ʻȘtefănești 22ʼ, ʻCostate 21ʼ and ʻChihlimbarʼ) and the indirect organogenesis in two genotypes (ʻArgeș 20ʼ and ʻCostate 21ʼ). Morphological characteristics of anther-derived plants from ʻArgeș 20ʼ variety, grown in greenhouse conditions (growth rate, features of leaf, flower, and fruit), as well as analyses with nine SSR markers (banding patterns, the coefficient of genetic similarity, and the polymorphism information content) in DNA samples from each regenerant and the donor variety, provided clear evidence of the occurrence of spontaneous genetic variation during in vitro anther culture, and of the existence of somaclonal variation in regenerated plants. The amplified products obtained with SSR primers revealed a total number of scorable bands of 160 and a mean percentage of polymorphic bands of 21.09%. Two out of the nine tested primers, SSR63 and SLM6-7 proved to be efficient in detecting genetic differences not only among regenerants but also between them and the donor genotype.

The methods applied for DNA extraction from must and wine samples with monovarietal origin are presented and discussed aiming to prove the quality of extracted DNA and its good properties for further use in molecular tests. In the present research were compared four different DNA extraction methods from must and wine samples obtained from eleven V. vinifera varieties (five grapevine varieties for white wines and six grapevine varieties for red wines, respectively). Taking into consideration the amounts of obtained DNA, the concentrations and purities of the final DNA extracts, were stood out two modified methods. For all must samples, very efficient was the second method, which allowed obtaining a mean value of 87.9 ng µl-1 for the DNA concentration with 1.55 purity. Among the tested procedures, for monovarietal wine samples, the fourth method proved to be the most efficient which brought a mean value of 64.7 ng μl-1 for DNA concentration with 1.66 purity. This method adequate for wine samples involves two CTAB solution treatments and the RNase treatment applied before DNA resuspension. The DNA from must and wine extracts and the DNA from leaves of the corresponding grapevine varieties were amplified with five specific microsatellite primers (VVS2, VVMD27, VVMD32, VrZAG79 and VrZAG62). The aspects of pattern profiles were analysed in parallel and proved that the extracted DNA was suitable for amplification with these specific V. vinifera primers. The two selected extraction procedures are considered good for research purposes and ensure obtaining of good-quality extracted DNA from musts and one-year old wines.

This paper presents a methodology of obtaining whole tomato plants from anther culture and their characterization. Year 1: the initiation of anther cultures and in vitro development of the new regenerated structures. Year 2: phenotypic characterization of plantlets acclimatized to ex vitro conditions, and their molecular analysis with SSR markers. Year 3: morphological characterization of plants obtained by germination of seeds from plants that fruited in the previous year and their molecular analysis with SSR markers. The phenotype descriptors and the SSR markers revealed differences among the regenerants and the donor variety. The uniformity of the genetic profiles with SSR markers in plants obtained from seeds of androgenic plants, but with several differences in comparison to anther-donor plants, indicates that some of the regenerated plantlets may have microspore origin