Agriculture Reference
In-Depth Information
CHAPTER 12
PHENOTYPIC CHANGES IN
DIFFERENT SPINACH VARIETIES
GROWN AND SELECTED UNDER
ORGANIC CONDITIONS
ESTELLE SERPOLAY, NICOLAS SCHERMANN, JULIE DAWSON,
EDITH T. LAMMERTS VAN BUEREN, ISABELLE GOLDRINGER,
AND
V
É
RONIQUE CHABLE
12.1 INTRODUCTION
Seed is an input of importance in agriculture. For each crop, farmers have
to choose, according to their farming system, from a range of different
types of varieties, based on genetic, phenotypic, commercial, social or cul-
tural characteristics. In Europe, the seed market is regulated: commercial-
ized seeds have to meet a number of standards set by law. The main one is
the registration of the variety in an official catalogue, which requires it to
meet Distinctiveness, Uniformity and Stability (DUS) criteria [1]. These
criteria are evaluated by visual assessments in trials performed by special-
ized institutions. Today, most marketed varieties (created by seed com-
panies) are F1 hybrids or pure lines, which are visually very uniform and
stable since they are genetically homogeneous (all the plants of the variety
have the same genotype). Other types of varieties, like populations or open
pollinated varieties are less homogeneous (more diverse) from a genetic
