No abstract

No abstract

No abstract

No abstract

The tribe Leucocoryneae is taxonomically and cytogenetically complex, mainly due to its extraordinary morphological and karyological variation. Robertsonian translocations had long been recognized as a central factor contributing to karyotype diversity within the Leucocoryneae, but so far no major tendency prevailing on the observed complexity of karyotype formula among species has been identified. The assessment of nuclear DNA contents by flow cytometry using propidium iodide in 23 species, representing all genera within the tribe, showed a monoploid genome size variation of 1Cx = 9.07-30.46 pg denoting a threefolds fluctuation. A highly significant linear association between the average DNA content per chromosome arm (2C/FN) and the monoploid genome size (1Cx) is reported for the first time and identified as a novel indicator of a trend governing karyotype diversity within Leucocoryneae. This trend shows that a reduction in DNA content per chromosome arm is influencing and has shaped karyotype evolution of different monophyletic groups within the tribe despite the complex karyotype diversity and apparently contrasting patterns of genome sizes.

BACKGROUND: Given the contradictory information available concerning the potential beneficial effects of organic production on food quality, there is a need for studies that determine the real effect of cropping systems on fruit quality. A two-year farm study was therefore conducted to assess differences in the mineral composition and sensory quality of pepper (Capsicum annuum L. cv. Quito) fruits cultivated in organic (O), low-input (LI) and soilless (SL) systems. Twenty-four greenhouses were selected following strict criteria in order to reduce the influence of environmental conditions and accurately and realistically reflect commercial production systems.

BACKGROUND: The aim of this work was to study the effects of organic (O), low-input (LI) and soilless (SL) cultivation on pepper nutritional quality and antioxidant activity. For that, 24 commercial greenhouses were selected following strict criteria in order to reduce the influence of environmental conditions and realistically reflect commercial production systems. Fruits were harvested at two maturity stages (green and red) and three harvesting times during two consecutive years.

Axonopus is a largely Neotropical genus comprising about 85 species. Many classifications have been proposed based exclusively on morphological characters. Our studies, including both molecular and morphological data, suggest that Axonopus is paraphyletic due to the inclusion of Gentrochloa and Ophiochloa. Considering that there are no strong morphological traits that differentiate either Gentrochloa or Ophiochloa from Axonopus, we propose the following new combinations: Axonopus singularis, comb, nov., Axonopus bryoides, comb, nov., and Axonopus hydrolithicus, comb. nov. We also suggest the need to review the infrageneric classifications taking into account both morphological and molecular data.