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g'l'UDY o�· THE EFFEG'l'S o:� DIFFER;;:N'l' BASE POPULJ•TIONS ON rH:: ->IM; AND VARIABILirt OF �HORT-'.r�RM R:-:..:;PONSF..S TO ·'ELECTION IN
liRCSOPHILA
A thesis subaitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy
at
Massey University
VIOLEr P M ENG CHIA
1971
I.
II.
Ill.
IV.
TAB L E OF C 0 N T E T S
INTRODUCTION
R:!:VIEW OF LITE:RA TUBE
A. PATrERNS OF SELECTION RtsPONSE
B. FACTORS AFF"'CTDG SELECTION RK1PONSE 1. Base populatione
2 . Selection traits
(1) Major components ot fitness (11) Characters l.:ith moderate effects
on fitnese
(iii) Characters with little direct effects
on fitness 3· Methods of selection
�. Population size and selection intensity
5· Mating systems 6. EAvironment
MA l'l;Rl:,LS I ND METHODS
A. ORGANISM
B. "BDOMINAL BRISTLE CH RACTER
C. BASE POPULATIONS
1. De cription ot baae pop11la tioae 2. Results and discu eion
HERITABILITY ESTIKA
BASE POP 'liONS A. IlftRODUC!IO
OF 1' E OBEGO -R l) .,
1
12 12 20 21
25
27 32 40
59 59
v.
B. MAT�RIALS AND METHODS C. RESUL'rS
1.. Oregon-R base population
63 66 66
( 1) Parent-offspring regression analysis 66
(ii) Diallel analysia 67
2.. +3 base popuJ.ation 69
(i) Parent-offspring regression analysis 69
(ii) Diallel analysis 69
:0. DISCUS�ION
,; -LECTION �X.PERIKENT
A. MATI!:RIALS • ND l�.E'l"HODS
1. iieplicaUons
2. Control
3· ;election procedure
B. SKLSCTION Rt ·utrs
1. General observations
2. Presenta tion of basic data
(i) Respon�e of mean bristle number (11) Phenotypic variance
( 11.1) Coefficient of variation
(iv) Realised heri bilit7
c. ANALlSI.:i OF :�ELECTION RE..'>PONSE 1. AYerage rate or respoaaa
(i) Recreaaioa coefficient (11) •• rea -·
(ill) Iatra-liae 4J..fferenoea reapoaae
(1y) latar-U.Ae differeaoea rea ...
ill •••rap ill •••r•c•
(y) Pattenut of two-dlrecU.o-1 ,... ....
71
73
?3 '73 '75 '7'7 8o Bo
81 83 91 96 97 101 101
lOit 112 11?
120
VI.
2. Realised heritabilit7 127
(1) Intra-liDe differences 1D
realised heritabilitJ 127
(U) Inter-ll.Jle difference• ill
realised heritabilitT 133
(111) Patt rllS of two-directional respon!ie 135 3· Variab111t7 between replicates withiD
selection lines (1) Introduction
(1i) Methods or anal7sis and results ... Discussion
D. PREDICTION OF $EL�CTION RS5PONSE
1. HeritabilitJ
2. Average response rate
3· Discussion
GE't'l.:.riC I i�ALYSES OF �ELi;;CTFD LIN£3
i\. ,>.NALYSE.:> OF +3 EIGH Jt;LECfiON LINE
1. Heritability esti��ations of the +3 high selection liae
(1) Materials and •ethoda {11) Results and di cussion
z. Crosaiag between +3 hi&h and low selection 11Des
B. RELAUTION OF SELECTION
C. CHROMOSOME ANALYSIS
1. Mate-ria.la nd •• eta
'· Dlecaae1oa
l. Rahrlala d •thod•
137 137 138
145 147 14?
152 156
159 159
159 159 16o
163 166 168 168 169 17 ..
117 119
VII.
2. ObserYatioas aad results
(1) FrequeDCJ of recessiye 1ethals (11) RelatiYe Yiabilities
(iii) IDter ctiona 3. DiacuaaioD
E. DISCUSS IO
G:.:N:•:RAL DISCU:.;SION
SUMMARY
ACKNC.l.'LEDGEKENTS
REFEHEliCES
1•·
182 183 186 188 189 190
193 199 203
204
Table
1
2 3
5 6
? 8
9
lO(a)
lO(b)
ll(a)
ll(b)
· 12(a)
LIS T 0 F TABLES
Mean abdominal bristle nuaber of D. melanogaeter b7 strain, reciprocal cross and sex
Para etere of the baee populatione
Expected composition of the heritabilit7 eetiaates derived from the parent-offspring recreseion
analysis and the diallel analJsis
Parent-offspring regression estimates of heritab
ility for abdoainal bristle number in the Oregon-R base popttlation
Analysis of variance of the diallel cross in the Oregon-R base population
Parent-offspring regression estimates of heri tab
ility for a bdotainal brie tle number ill the + 3 base population
�nalJais of variance of the diallel cross in the
+3 base population
Components of variance for abdo inal bristle number in different base populationa
Experimental plan and ita code designations
Mean abdominal bristle nu•ber of individual selection replicates and the controls (female data)
Me abdominal briatle nu•ber of in41vidual selection replica tee and the control ( aale data)
PhenotJPiC •ariaDcea of individual aelectioa replicate• aad eo trola {feaal.e data)
Pheaotypic •ariaacea of in 1v1clual aeleotio rep11ca\ea an controla (aale 4ata)
Coefficieat of •ariaUoa (�) •f ln4iridual aelecUo• repli.oatea aa4 oontrola (feaal.e uta)
t refers to following pace.
••
62
66 68
69 70
71
?9 r 82
t90
f90
f96
�able
l2(b) 13
l�
15 16
17 18
19
20 21
22
23
25
21
Coefficient of variatioa (�) of individual selection replicat s and controls (��ale data)
Average realised heritabilitiea of selection lines for each generatioa (sexes combined) Analysis of variance.
resresaion
Analysis of variance.
regression
De�iations froa linear
Deviations from linear
t.verae;e respoase rate from the linear regression of response against generatioa number of the
erose high replicates
Test for homogeneity of regression coefficients of the Cross high selection line (female data)
Test for homogeneitJ of within-replicate regression coefficients of t he high selection lines. Sumaary of F-tests
Test for homogeneity of within-replicate
regression coefficients of low selection linea (female data). Summary of F-testa
Mean response for tig�. and low selection li.J:uts
Compariaon of two methods of eaauring response (bristle nu•ber per gener&tion) of the sele ction linea
Co parison of the standard errors of the t•o estimates of average responae rate
Confidence intervals of average response rates of individual replicates of high aelectioa liaes Regreasioa coefficients of indiYidual replicates of low selection linea aad interYal estiaatea of averaae regreaaioa coefficients
!'-teat for the hoaogeneit7 of averap resreaaion coeff1cieata of liae selected ill the aa•
dlrectioa. Suaa&rJ of F-testa
Iater.al eatiaatee f r t e ••era e aelectioa reapoaaea ( ri8tle ... ber per ceneratioa) ot hl aa4 low aelecU.Oa lbee
J'88eb7 of aelecti r .. poue. AYerage
resreaaioa coefficieate of hiah aa4 low aelectioa
llaea
n.
f 96
lOO
105 107
108 110
111
112 114
115 117 118
f 119
121
'fable
28 29(a)
29(b)
31
32
33
34(a) 34(b)
35 36
}7
''
41
Intra-replicate realised heritabilitiea {regre ion coefficient) (sexes s par te)
test for ho�geneit7 of intra-replicate
regression coefficients (realised heritab
ilitiea) o! high selection liAes. Suaaary of F-tests
Test for homogeneitJ of iatra-replicate reiJ'easion coefficients (realised heritab
ilitiea) of low selection linea. Svmmar�
of r-testa
The 95% confidence interYale of realiae heritabilities of individu 1 replicates (iD :percentage)
F-tests for homogeneitJ of average realised heritabilities of lines selected ia the same
direction. SuccarJ of F-tests
Confidence iftteryals of average realis d
heritabilities {�) of high and low selection lines
Asymmetry of selectioa responses. Average realised heritabilities of high and low selection l.ines
Vari�nce components between and within replicates
of high sele c ti on lines
Varianc components be tweea and within replicates
of low selection lines
Rate of increase in inbreedins per generation
Inbreeding leYel (F) of election lines and replicate differenc a due to senetic rift (VB)
( exN co•bine4)
Sumaar7 of realise an4 pre41cte4 aeritabilitiea (h2) of Oreson-a ancl +3 'base populati011a
O..iatioae of the eatiaat the ••erase heritabilit7 paeraU
heritabllitJ froa f the first electioa
RN ee per a•aeratio !l"ecliote4 fr a•neratioa real.iae4 her1ta1t111t1ea
firat
Co•par18oa of obaerftd witJa e c\84 r .. poaa•
(�iatle er/ae tloa )
eritab1U.t.J eetnatea of the +} hip selecUo
liae (Qe .l't)
'11.1..
128
129
1}0
131
133
134
135 f 139
f 139 141
150 15) 15-\
161
46
47
Reciprocal crosects between +3 hi&h aelectioa line aad +3 lo• electioa replicates
Mating echeae for chroaoao•e aaaaya of election replicates agaiaat Yl •• tester stock
AaalJaia of yariaace of female abdominal bristle nu.11ber fros cbromosoEe assays
Chroaoso e aasa7e of selection replicates against Yl se stock (!eule data)
Mating system utilised for detecti.ng recesaiYe lethala 1 second and third chromosomes in selectio replicates
Method of analysis of the effects of the secon4 and third cLromoaoae ho ozygotes of the selection replicates on Yi ability
FreqaenCJ of lethal second and third chromes�•••
in high and low selection replicates
Viability indices of second (S) and third ( T)
chro�osome homozygotes of the selection replicates as well as interaction (I)
l61t t 169
172 t 173
181
184
187
Fipre l(a)
l(b) l{c)
l(cl)
l(e) l(f)
l(g) 2 }(a) 3(b) }(c) 3(4) }(e) }(f)
L I S T 0 F FIGtJR�S
Selection response of the Oregoa-R population (!eaale data)
Selection respon e of the Oreson-R pop�lation (male data)
Selection response of the +3 population {te!Dale data)
Selection response of the +3 population (Ill& le cla ta)
Selection respons of the Oross population (fe ale data)
�election response of the Cross population (male data)
Average selection response of the Oregon-R9
+3 and Cross population& (female data)
Divergence of selection response between high
and low selection lines
Phenotypic variance of individual replicates of Oregon-R (!e ale data)
l'benot;ypic variance of individual replicates
of Oregon-R (male data)
Phenotypic variaace of individual replicatea of +3 (fe ale data)
Phenotyplc variaece of individual replicate-a
of +3 (sale data)
Phenotyplc varialloe of izulividual replicaua of cro s (feaale clata)
Phello typlo Y&ri&ace of iacl1Yldll
of Crou (lllll.e clata)
t refer• tollo•l•a paa•·
f 83 t 81t t Bit f 85 f 85
f 86
f 90
f 91 f 91 f 92 f 92 t 9.3
f 9}
Fipre
5
6
7
8
9
10
11
12
13 1 ..
15
Comparison ot the mean phenotypic variance• ot
high and low selection linea and controls ot
Oreson-R, + 3 and Cross
Co•pariaon ot the coetficieat ot variation or
the high and low selection linea and controls ot the Oregon-R, +3 and Cross
Coabined sexes realised heritability for high
and low selection linea of Oregoa-R, +3 an d Crosa
Comparisons of the two estiaatione of response
per generation - regression coefficient aad responee/t - of Oregon-R9 +3 and Cross selec
tion line s (feaale data)
Coaparison of standard rrors of aver ge recresaion coefficient and aean response of the Oregon-R, +3 and Cross selection liaee
( f e a le data )
Confidence intervals of average response rate tor individ�al replicates of high selection lines
Total respon�e plotted against cumulated
selection differential of high and low
selection lines of the Oregon-R, +3 and Cross populatione (female data)
Confidence intervals of realised heritab
ilitiee of individual replicates
Comparison of observed between replicates variance with expected drift variance
(sexes co binecl)
F-ratio of selection linea (sex a coabined)
Coaparison of predicted reapo ea with observed average reapoaae over fourteea selection gener tiona
Bffecta of relasiac aelectioa� DeYiatioa•
of aelected lia• froa the eo trol liae
t 9,.
f 95
f llZ
f 116
t 117
r 126
f 131
!140 t 1 .. 3
f 15 ..
1 166
