Efeito de solo previamente cultivado com plantas aromáticas na germinação e no desenvolvimento inicial de alface / Outcomes of soil previously treated with aromatic plants in the germination and early growth of lettuce

RESUMOO objetivo desse trabalho foi verificar o efeito do solo pré-cultivado com plantas aromáticas na germinação e no desenvolvimento inicial de plântulas de alface cv. Simpson. A pesquisa foi realizada na Embrapa Hortaliças, Brasília, em bandejas mantidas em casa de vegetação. O experimento foi conduzido em delineamento experimental inteiramente casualizado, com três repetições e onze tratamentos: solo pré-cultivado com hortelã-comum (Mentha x villosa), hortelã-brava (Mentha arvensis), hortelã-pimenta (Mentha piperita), Mentha spp., capim-citronela (Cymbopogon winterianus), capim-limão (Cymbopogon citratus), manjericão de folha larga (Ocimum basilicum), manjericão de folha roxa (Ocimum gratissimun), tomilho (Thymus vulgaris), sálvia (Salvia officinalis) e solo da mesma área sem cultivo prévio de planta aromática (controle). Aos 30 dias após o semeio, foram avaliadas: índice de velocidade de emergência (IVE), taxa de sobrevivência (TS), número de folhas (NF), comprimento da raiz principal (CRP) e da parte aérea (CPA), massa fresca da raiz (MFR) e da parte aérea (MFPA) e massa seca da raiz (MSR) e da parte aérea (MSPA). Os dados foram submetidos à análise de variância e teste de Tukey a 5% de probabilidade. Houve diferença significativa em relação ao IVE, sendo que o tratamento com C. citratus afetou negativamente a emergência das plântulas. O tratamento com M. arvensis apresentou uma TS de apenas 16% das plantas aos 30 dias após a semeadura. O NF foi menor no tratamento com M. arvensis, diferentemente de todos os demais, exceto S. officinalis. A MRF e MFF foram estimuladas pelo tratamento com T. vulgaris sendo superior a todos os outros tratamentos. Os resultados obtidos permitem concluir que houve efeito negativo de M. arvensis e positivo de T. vulgaris no desenvolvimento inicial de plântulas de alface.

ABSTRACTThis study aimed to verify the outcomesof the soil previously treated with aromatic plants in the germination and early seedling growth of lettuce var. Simpson under greenhouse conditions. The trial was developed at Embrapa Vegetables, in Brasília, Brazil in a completely randomized design with three replications and composed by eleven treatments as follow: soil cultivated with apple-mint (Mentha x villosa), wild mint (Mentha arvensis), peppermint (Mentha piperita), Mentha spp., citronella (Cymbopogon winterianus), lemon grass (Cymbopogoncitratus), basil (Ocimum basilicum), african basil (Ocimum gratissimun), thyme (Thymus vulgaris), sage (Salvia officinalis) and soil from the same area without prior cultivation of aromatic plant (control). The emergence velocity index (IVE), the survival rate (SR), the number of leaves (NL), the length of the main root (CRP) and the shoot (CPA), the fresh mass of the root (MFR) and the shoot (MFPA) and the dry mass of the root (MSR) and the shoot (MSPA), were evaluated 30 days after the sowing. The data were submitted to analysis of variance and Tukey's test at 5% probability. There was a significant difference regarding the IVE, in which the treatment with C.citratus negatively affected seedlingappearance. The treatment with M. arvensis showeda TS of only 16%at 30 days after the sowing. The NF was lower in the treatment with M. arvensis, differently from all the others, excepting the cultivation withS. officinalis. The MFR and the MFPA were stimulated by the treatment with T. vulgaris, which was higher than all the other cultivations. The obtained results showed that M. arvensis had a negative influence,while T.vulgaris presented a positive outcome in the early development of lettuce seedlings.

Genetic divergence among Brazilian garlic cultivars based on morphological characters and AFLP markers.

Outside its centers of origin, garlic propagates only asexually. Since asexual reproduction leads to the absence of meiotic recombination, the main garlic cultivars available for cultivation have arisen from the accumulation of somatic mutations in early cultivars. Thus, it is common for a single clone to have different names in different regions. This study aimed to evaluate the genetic diversity of 20 garlic cultivars by using morphological characters and amplified fragment length polymorphism (AFLP) markers to identify possible duplicate cultivars. We assessed 28 morphological characters related to the leaves, bulbs, and bulbils of the garlic plant and divided them into two categories: quantitative and qualitative (14 characters each). For molecular marker-based analysis, we used three AFLP primer combinations. Genetic divergence was calculated using the Jaccard coefficient; the cultivars were grouped using unweighted pair-group mean analysis. The average genetic divergence detected using the morphological characters was 2.30 (range, 0.45-4.70). Plant height and coat adhesion exhibited the highest divergence among the cultivars. The average genetic diversity based on AFLP data was 43% (range, 0-79%). Dendrograms derived from both techniques divided the cultivars into two groups: noble and semi-noble. Together with the divergence within groups, the correlation between morphological and molecular data suggested that the cultivars in the noble group had greater phenotypic stability than those in the semi-noble group. Analysis of Jonas and Quitéria cultivars using these two techniques revealed only slight differences, suggesting that these cultivars may be clones or have a high degree of kinship.

Genetic diversity studies of Brazilian garlic cultivars and quality control of garlic-clover production.

The garlic cultivars grown in Brazil evolved from somatic mutations and clone selection by breeding programs and by the introduction of germplasm from other countries. Morphological characters have been used to differentiate these cultivars. Two hundred and six random amplified polymorphic DNA markers were utilized for a diversity analysis of the 17 most planted garlic cultivars in Brazil. Bootstrap analysis showed that the number of markers was efficient and sufficient to obtain a coefficient of variation of 10%. Similarity varied between 16 and 98% and cluster analysis showed that, in general, genetic similarities correlate with morphological characters of the cultivars and production cycle variation. High bootstrap values at most of the nodes supported the dendrogram stability. The grouping of most varieties agreed well with previous reports based on morphological characters. As a vegetative-propagated species, viral diseases are a key problem regarding production and quality of the bulbs, causing gradual loss of yield and decrease in storage capacity. To improve the health quality of garlic seed, a virus-free stock of garlic cloves of the Amarante cultivar was obtained. The ability to distinguish garlic cultivars to detect varietal mixing after in vitro multiplication is extremely important, since correct identification is not possible until bulbs are produced. Random amplified polymorphic DNA markers were also used to differentiate cultivars while they are in vitro and not amenable to morphological discrimination. No difference was identified between the fingerprints of the virus-free or of the infected bulks of Amarante, showing that there was no clove mixing in the handling of material in the clonal multiplication phase.

Genetic diversity studies of Brazilian garlic cultivars and quality control of garlic-clover production

The garlic cultivars grown in Brazil evolved from somatic mutations and clone selection by breeding programs and by the introduction of germplasm from other countries. Morphological characters have been used to differentiate these cultivars. Two hundred and six random amplified polymorphic DNA markers were utilized for a diversity analysis of the 17 most planted garlic cultivars in Brazil. Bootstrap analysis showed that the number of markers was efficient and sufficient to obtain a coefficient of variation of 10%. Similarity varied between 16 and 98% and cluster analysis showed that, in general, genetic similarities correlate with morphological characters of the cultivars and production cycle variation. High bootstrap values at most of the nodes supported the dendrogram stability. The grouping of most varieties agreed well with previous reports based on morphological characters. As a vegetative-propagated species, viral diseases are a key problem regarding production and quality of the bulbs, causing gradual loss of yield and decrease in storage capacity. To improve the health quality of garlic seed, a virus-free stock of garlic cloves of the Amarante cultivar was obtained. The ability to distinguish garlic cultivars to detect varietal mixing after in vitro multiplication is extremely important, since correct identification is not possible until bulbs are produced. Random amplified polymorphic DNA markers were also used to differentiate cultivars while they are in vitro and not amenable to morphological discrimination. No difference was identified between the fingerprints of the virus-free or of the infected bulks of Amarante, showing that there was no clove mixing in the handling of material in the clonal multiplication phase.