ABSTRACT

The medicinal properties and ornamental value of Aloe vera have been recognized by civilizations throughout the world and are described in ancient documents, including the Bible. Its therapeutic potential is demonstrated every day in the many laboratories, medical centers, and traditional hospitals that study and evaluate natural healing alternatives for diseases such as cancer, as well as gastrointestinal, skin, cardiovascular, respiratory, and metabolic disorders. Their investigations have found that the

CONTENTS

25.1 Introduction ......................................................................................................................... 847 25.2 Composition and Therapeutic Uses ....................................................................................848 25.3 Origin .................................................................................................................................. 851 25.4 Etymology ........................................................................................................................... 851 25.5 Taxonomy and Evolution ..................................................................................................... 853 25.6 Botanical and Ecological Features ......................................................................................854 25.7 Pests and Diseases ............................................................................................................... 859 25.8 Genetics ............................................................................................................................... 862

25.8.1 Karyotype.............................................................................................................. 862 25.8.2 Constitutive Heterochromatin ............................................................................... 865 25.8.3 Haploid Chromosomes .......................................................................................... 865 25.8.4 Karyological Abnormalities ..................................................................................866 25.8.5 Molecular Markers (RAPD-PCR) ........................................................................ 870

25.9 Plant Breeding ..................................................................................................................... 871 25.9.1 Mutagenesis ........................................................................................................... 871 25.9.2 Polyploidy .............................................................................................................. 871 25.9.3 Hybridization ........................................................................................................ 871 25.9.4 Genetic Transformation with Agrobacterium ....................................................... 874

25.10 Micropropagation ................................................................................................................ 875 25.11 Conclusion ........................................................................................................................... 876 Acknowledgments .......................................................................................................................... 876 References ...................................................................................................................................... 877

administration of A. vera extracts acts successfully as a treatment to alleviate these conditions, both by itself or as a coadjuvant of formal medicine effects. There are currently over 800 km2 cultivated with A. vera, mainly in dry regions in the Americas, southern Europe, Africa, Arabia, India, China, and Australia; they produce the raw material for the food, pharmaceutical, and cosmetics industries.