UNIVERSITE DE BOURGOGNE THÈSE Yongbo LIU - Université de ...

The fruit of wild radish is a silique with a slender beak, constricted between seeds; it is easy to
break i nto d istinct s egments ( articles) w hen m ature, an d e ach a rticle co ntaining o ne s eed.
Silique ch aracteristics i n t he s even cages i n 2 008 w ere m easured, i ncluding d iameters o f
largest and smallest articles, diameter of largest and smallest constrictions, number and total
length of articles per silique, silique length (including the beak) and silique weight (Fig. 4.2).
Beak le ngth ( silique le ngth- total le ngth o f a rticles p er s ilique) and a rticle w eight ( silique
weight/ n umber o f a rticles p er s ilique) w ere estimated. M ean v alues o f d iameters o f th e
largest an d s mallest ar ticles an d co nstrictions w ere calculated as ar ticle d iameter an d
constriction diameter, respectively.
A s ample o f s eeds dehulled from articles o f e ach population was germinated i n
greenhouse and grown in pots placed at random at 15-25°C under natural light in 2009. T he
flower characteristics o f t hree t o s ix f lowers p er p lant an d 2 9-42 pl ants pe r r egion w ere
measured, including length and width of two adjacent petals per flower. Petal color was noted
in white, pale, yellow and intense yellow, and petal patterns were classified as round or long.
Mean values of length and width of two adjacent petals were estimated as petal length and
petal width, respectively. Petal shape (petal width/ petal length) and flower area regarded as a
disk (π× petal length^2) were estimated (Fig. 4.3).
Field experiment
The s ame s eeds as ab ove were germinated i n g reenhouse i n J anuary and ag ain i n February
2009 in order to insure getting plants flowering at the same time as a sulfonylurea-resistant
oilseed rape line grown in a field at the INRA experimental station. They were grown on a
bare ground in 20 L pots with water tank, one plant per pot. 41 NM pots and 40 BT+BG+DM
pots with plants at the onset of flowering were transferred in the field when the sulfonylurea-
resistant oilseed rape plants started flowering. Already opened flowers of wild radish were cut
before putting pots in the field. Pots were put 10 meters apart each other, at random along ten
rows in a 1 ha field sown at oilseed rape density of 40 pl m -2 . Each pot position was located
by GPS.
Wild radish was harvested when the first siliques turned brown. The vegetative parts
were separated from the pods and dried in an oven for 48h at 80°C and weighted. Number of
siliques and seeds per plant and weight of s eeds per plant were m easured. Per seed w eight
(seed w eight/ s eed num ber) a nd r eproduction a llocation ( seed w eight/ pl ant w eight) were
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