Physiological quality, anatomy and histochemistry during the development of carrot seeds ( Daucus carota L.)

Abstract

The adequate time for carrot seed harvest influences its physiological quality. The objective of this study was to evaluate physiological, anatomical and histochemical changes in carrot seeds harvested at different stages of development and to establish the most appropriate harvest time. Secondary umbels were harvested at 14, 21, 28, 35, 42, 49, 56 and 63 days after anthesis (DAA). For seed anatomical and histochemical characterization, sections were stained with Toluidine blue stain, Xylidine Ponceau, Lugol's iodine, Sudan Black B and submitted to polarized light. Seed moisture content, seed dry matter, germination, first count, emergence percentage and emergence speed index of seedlings were evaluated. Cultivar Brasília carrot seeds at 14 DAA are in cell division and expansion. In addition, as lipids were identified in the endosperm, despite the seed low dry matter. At 21 DAA, reserve substances such as protein and starch were also identified. Along the seed development process, deposition of lignin occurs in the endocarp cells, and this collapsed lignified layer represents the resistance layer of the seeds. Physiological maturity, represented by the maximum dry matter accumulation, occurs at 35 DAA, with the endosperm occupying almost all volume of seeds, the embryo occupying a small cylindrical region and the integument showing a single layer of cells. At this time, the seeds presented 56% moisture content and the color of the pericarp is green-yellow. Maximum seed germination and vigor occurred at 30 DAA, just before physiological maturity was reached (35 DAA). Thus, the ideal time to harvest the seeds of cultivar Brasília is from 30 DAA, where the seeds have maximum physiological quality.Index terms: Maturity; harvest; reserve substances; germination; vigor. RESUMOA colheita das sementes de cenoura no momento adequado tem reflexos diretos sobre a sua qualidade fisiológica. O objetivo do trabalho foi avaliar as alterações fisiológicas, anatômicas e histoquímicas em sementes de cenoura colhidas em diferentes estádios de desenvolvimento e estabelecer a época mais adequada para a colheita. Foram colhidas umbelas secundárias aos 14, 21, 28, 35, 42, 49, 56 e 63 dias após antese (DAA). Para a caracterização anatômica e histoquímica os cortes foram corados com Azul de toluidina, Xylidine Ponceau, Lugol, Sudan black B e submetidos à luz polarizada. As sementes foram submetidas aos seguintes testes: grau de umidade, matéria seca, germinação, primeira contagem, porcentagem e índice de velocidade de emergência de plântulas. Sementes de cenoura 'Brasília', aos 14 DAA, encontram-se em divisão e expansão celular e apesar da reduzida matéria seca, lipídios foram identificados no endosperma. Aos 21 DAA, além de lipídios, proteínas e amido foram identificados. A maturidade fisiológica das sementes ocorreu aos 35 DAA, com o endosperma ocupando praticamente todo volume das sementes, o embrião ocupando uma pequena região cilíndrica e o tegumento apresentando uma única camada de células. Nesta fase, as sementes apresen...

Determination of Chlorophyll and Carotenoids Present in the Seeds of the Plant Family Apiaceae and the Impact on Seed Quality

“…The carrot germination value of about 80 % was found in variety of "Brasilia" in physiological maturity (35 DAA), and it has grown to full maturity even slightly. The value of energy of germination was only around 60 % (Miranda et al, 2017), but in our results it was higher around 87 %, except "Jolana" with only 77 %. In the case of parsley variety "Lisa Preferida", represented by four commercial lots, 62 -63 % germination was lower than the minimum recommended for certified seed commercialization (80 %) and energy of germination had values 51 -56 %.…”

“…The largest difference between seedling emergence and germination was observed for the celery varieties, where the seedling emergence reached only 40 %. Seedling emergence of carrot variety "Brasilia" was around 80 % from 28 DAA to 63 DAA (Miranda et al, 2017), but in our results carrot varieties show values around 89 %, except "Jolana" with 77 %. In the case of parsley variety "Lisa Comum", where four seed lots were used, values of seedling emergence ranged from 48 -81 % (Tunes et al, 2013).…”

Protective effect of Kumquat fruits and carrot seeds extracts against brain aging in rats

“…Also Nouri and Shafaghatlonbar (10) declared that the essential oil of kumquat was considered a potent antioxidant. Carrot seeds ( Figure 1) produced when flowering process is induced; and the plant turns from the vegetative phase to the reproductive phase thus producing a rod or floral tassel at the end of it an umbels which carry the seeds (11). Although the carrot plant is planted primarily with the aim of obtaining roots, but the seeds are used as a flavoring agent in many food products and cosmetics in addition to its utilization as medicinal purposes.…”

Conservation of Garcinia imberti Bourd. through seeds

“…dormancy is overcome by exogenous application of GA3 and light in Rheumemodi seeds reported by Kandari et al (24). Several cultivated species are uninterested to light to sprout; but, the light is very essential and it stimulates seeds of various wild species (25). Alternating temperature treatments with light dramatically improved the germination process of Cuphea viscosissima dormant seeds reported by Widrlechner and Kovach (26).…”