GENETICS AND LINKAGE OF ISOZYME MARKERS AND RESISTANCE TO SEEDBORNE ASCOCHYTA INFECTION IN LENTIL
Date
1994-03
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Degree Level
Masters
Abstract
The possible linkage of isozyme and morphological trait loci with
genes for resistance to ascochyta blight, caused by Ascochyta fabae f. sp.
lentis Gossen et aI.,was
investigated in lentil (Lens culinaris Medikus).
Parent lines, F2 populations and a susceptible check, Spanish Brown lentil,
were screened for ascochyta reaction in a field experiment at the North
Seed Farm in Saskatoon durings ummer 1992. Parent lines were evaluated
for both foliar infection, using a disease scale of 1 to 9, and percent
seedborne ascochyta infection, using a seed plating technique. Individual
plants in eight F2 populations were scored for percent seedborne ascochyta
infection. The genetics and inheritance of 11 isozyme loci and 7
morphological trait loci were also studied in 12 F2 populations of lentil.
The susceptible check, Spanish Brown lentil, was very susceptible to
both foliar infection (9) and seedborne ascochyta infection (40%). Du Puy,
Eston, and CDC Richlea lentils showed highly susceptible reactions to both
foliar ascochyta infection (7to 9) and seedborne ascochyta infection (51to
57%). Laird lentil was
moderately resistant to foliar infection (5), but
susceptible to seedborne ascochyta infection (37%). Lentil lines, PI
339283, ILL 5588, PR 86-360, and PI 374118were highly resistant to both
foliar ascochyta infection rating (l to 3) and seedborne ascochyta infection
(0to 6.6%). The foliar ascochyta rating of Indianhead lentil was resistant (1) and moderately resistant to seedborne ascochyta infection (12%).
Resistance to ascochyta in ILL 5588 lentil was due to a
monogenic
dominant gene (Rail). One recessive gene, ral, was
responsible for
resistance to ascochyta in Indianhead lentil. The F2 population of
Indianhead x PI 345635 indicated that Indianhead carried two recessive
duplicate genes for resistance to seedborne ascochyta infection. The F2 of
Lairdx PI 374118 lentil segregated for two recessive genes for resistance
to seedborne ascochyta infection ,one each from Laird and PI 374118 lentil.
The inheritance of ascochyta resistance in PI 339283 lentil was governed
by two dominant complementary genes.
Four linkage groups of lentil, involving seven isozyme loci and
yellow cotyledon color, were constructed. Pgd-p and Skdh-p were linked
(35 cM), Aat-m and Me-2 were linked (4cM), Aat-p and Aco-I were linked
(16 cM), and Pgm-p and yc were linked (5 cM).
The dominant gene for ascochyta resistance, Ral was linked with the
isozyme locus Aat-p (29 cM) and the recessive gene, ral., was linked with
the isozyme locus Pgd-p (28 cM). Even though, both isozyme linkages are
weak, they can be used to study these areas of the chromosomes to help
screen for markers more
closely linked with genes for resistance to
seedborne ascochyta infection.
Description
Keywords
Citation
Degree
Bachelor of Arts and Science (B.A.&Sc.)
Department
Plant Sciences
Program
Crop Science and Plant Ecology