Mahmood, I.

Saxena, S.K.

Name not available

Relative susceptibility of different cultivars of tomato to Rotylenchulus reniformis in relation to changes in phenolics

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Notes brèves 
RELATIVE  SUSCEPTIBILITY OF  DIFFERENT  CULTIVARS  OF  TOMATO  TO 
ROTYL,ENCHULUS  RENIFORMIS IN  RELATION  TO  CHANGES  IN  PHENOLICS 
Irshad ~ " O O D *  and S.  K. SAXENA" 
Tomato is considered to be a good host for the 
reniform  nematode Rotylenchulus  renifonnis Linford & 
Oliveira, 1940 and little work has been carried out to 
determine  resistance to the  nematode  among cultivars. 
Rebois, Eldridge  and  Webb (1977) tested several tomato 
cultivars and wild Lycopersicon pimpinellifolium with  the 
reniform nematode  and reported some degree of resist- 
ance only in the wild species. Without resistant cultivar, 
it becomes necessary to  determine  the variety which is 
least  affected by infection. Hence Our objective  was to 
determine  the  least  inoculum  densities  at  which signifi- 
cant  reduction  in  growth of plant is observed  in  different 
cultivars. Changes in phenolics in different cultivars 
occurring with R. renifomais were determined  to ascer- 
tain if there is any  relationship  between the  damage of 
plants and the phenolics as a  result of infection. 
MATERIALS AND iMETHODS 
Two-week-old seedlings of twelve cultivars of tomato, 
raised in autoclaved soil,  were transplanted  in 15 cm Clay 
pots  filled with 1 kg  autoclaved soil, sand  and  compost 
mixture (70 : 20 : 10) and a week later they were 
inoculated with 10, 100 and 1 O00 juveniles of R. reni- 
fonnis. There were six replicates of each  treatment. The 
pots  were  randomised on a glass house  bench.  Uninocu- 
lated  plants served as control. 
After 60 days plant  growth  in  terms of total (foliage 
and roots) dry weight was determined and the popu- 
lation of the nematode counted from 200 g soil sample by 
using Oostenbrink elutriator together with Baermann 
funnel  technique. 
Total phenols were estimated from 100 mg of dry 
powdered sample of the whole plant by the  method of 
Biehn, Kuc and William (1968) using  Folin  Ciocalteau 
reagent (Bray & Thorpe, 1954) in  the  Bausch  and  Lomb 
spectronic 20-Colorimeter at 660 nm. The standard 
curve was plotted  against paracresol. The total O-dihy- 
droxy phenols were estimated  from 100 mg  sample  by 
the  method of Johnson  and  Schaal(1954),  using  Arnows 
reagent. The standard curve was plotted against cat- 
echol. 
The data were analysed by ANOVA and least square 
differences  calculated. 
RESULTS AND DISCUSSION 
Al1 the cultivars of tomato tested were susceptible to 
R. renifonnis to a varying degree (Tab. 1). Significant 
reduction in growth of tomato cvs. BCVI, Labonite, 
Marglobe,  N-Tropic  and  Trope  GRO-7 was observed 
even at  the  inoculum level of ten juveniles per kg soil and 
in al1 the remaining cultivars viz. Anahu, 67-B-1169, 
Burpees Heinz, Chicogrande, N-Pinky, Nemared and 
Sioux  showed  significant  reduction in growth at  inocula 
of 100 and 1 O00 juveniles per kg soil (Tab. 1). Al1 the 
cultivars of tomato  supported  the multiplication. The 
nematode  reproduced  on al1 the cultivars but  the  rate of 
multiplication  varied  between  cultivars. 
It therefore, appears that tomato cultivars Anahu, 
67-B-1169, Burpees  Heinz,  Chicogrande,  Nemared, 
' N-pinky  and  Sioux have greater minimum  threshold  for 
damage  to R.  renifonnis and  can  be  recommended  in  the 
event of the  absence of a  tolerant/resistant variety. 
The content of phenols and O-dihydroxy phenols 
(Tab. 1) increased in al1 the cultivars of tomato as a 
result of infection at al1 the  inoculum levels. Cultivars 
indicating more increase in phenolic showed less re- 
duction in plant growth together with low multiplication 
of reniform  nematode. It is thus concluded that as a result 
of infection with reniform  nematode  the level of phe- 
nolics increased. The increase in the level of these 
substances  in  different  cultivars was directly related to 
growth of plants.  Similar  correlation  between the  degree 
of resistance and  the rise in  phenolic  contents  due  to 
infection have been observed by several other workers 
(Giebel, 1974). 
* Section of Plant Pathology  and  Nevnatology, Department of Botany,  Aligarh  Musliln  University,  Aligarh-202 001, India. 
Revue Nématol. 9 (1) : 89-91 (1986) 89 
I. Mahmood & S. I<. Saxena 
Table 1 
Effect of different  inoculum levels  of Rotylenchulus renifornzis on growth 
of tomato  cultivars : changes  in  phenolics  and  nematode  multiplication 
Cultivars Nematode 
per pot 
Growth of plant 
Total dry wt. (g) 
Total phenolics mg 
per 100 m g  sample R = pf/pi 
Phenols O.D. 
Anahu 
67-B-1169 8 
BCVI 
Burpees  Heinz 
Chicogrande 
Labonite 
Marglobe 
Nemared 
O 
10 
100 
1 O00 
L.S.D.  (1 %) 
L.S.D. (5 %) 
O 
10 
100 
1 O00 
L.S.D.  (1 ?'O) 
L.S.D. (5 %) 
O 
10 
100 
1 O00 
L.S.D.  (1 %) 
L.S.D.  (5 '/O) 
O 
10 
100 
1 O00 
L.S.D. (1 '/O) 
L.S.D.  (5 %) 
O 
10 
100 
1 O00 
L:S.D. (1 %) 
L.S.D.  (5 "/O) 
O 
10 
100 
1 O00 
L.S.D.  (1 %) 
L.S.D. (5 "/O) 
O 
10 
100 
1 O00 
L.S.D.  (5 %) 
L.S.D. (1 "O) 
O 
10 
100 
6.35 
5.99 
5.18 
4.75 
0.255 
0.168 
6.10 
5.25 
4.20 
3.70 
0.229 
0.157 
5.75 
4.70 
3.60 
3.00 
0.180 
0.119 
7.00 
6.40 
5.50 
5.00 
0.745 
0.491 
6.80 
6.22 
5.30 
4.75 
o. 109 
0.072 
6.00 
5.10 
4.05 
3.50 
0.196 
O. 129 
5.80 
4.70 
3.60 
3.00 
0.306 
0.202 
6.50 
6.07 
5.10 
( 5.66) 
(18.42) 
(25.19) 
- 
- 
(13.93) 
(31.140 
(39.34) 
(18.26) 
(47.82) 
- 
(37.39) 
( 7.85) 
(2  1.42) 
(28.57) 
- 
( 7.85) 
- 
(22.05) 
(30.140 
(15.00) 
(32.50) 
(41.66) 
- 
(18.96) 
(48.27) 
- 
(37.93) 
( 6.60) 
(21.50) 
- 
0.500 
0.585 
0.635 
0.700 
0.009 
0.006 
0.415 
0.478 
0.518 
0.575 
0.009 
0.006 
0.393 
0.446 
0.493 
0.541 
0.007 
0.004 
0.480 
0.556 
0.601 
0.665 
0.007 
0.004 
0.465 
0.538 
0.583 
0.645 
0.007 
0.004 
0.423 
0.488 
0.531 
0.588 
0.006 
0.004 
0.355 
0.395 
0.445 
0.480 
0.003 
0.002 
0.498 
0.578 
0.623 
0.245 
0.283 
0.320 
0.375 
0.004 
0.003 
0.201 
0.226 
0.250 
0.304 
0.007 
0.004 
0.185 
0.208 
0.230 
0.283 
0.003 
0.002 
0.225 
0.257 
0.290 
0.345 
0.004 
0.002 
0.220 
0.252 
0.284 
0.337 
0.01  1 
0.007 
0.205 
0.230 
0.255 
0.310 
0.007 
0.004 
0.179 
o. 190 
0.210 
0.255 
0.004 
0.002 
0.240 
0.275 
0.31  1 
77.5 
28.5 
7.2 
- 
119.3 
43.8 
10.2 
- 
133.0 
46.9 
10.5 
- 
86.8 
41.2 
8.2 
- 
98.5 
34.2 
8.9 
- 
117.2 
43.8 
10.0 
- 
149.1 
43.8 
10.9 
- 
75.5 
29.0 
- 
90 Revue Nématol. 9 (1) : 89-91 (1986) 
Notes brèves 
N-pinky 
N-tropic 
Sioux 
Tr,ope GRO-7 
Table 1 (cont.) 
~~ 
1 O00 4.60  (29.23)  0.691  0.365  7.3 
L.S.D. (1 '/O) 1.276 0.009 0.005 
L.S.D.  (5 "/O) 0.842 0.006 0.003 
O 6.20 - 0.450 0.215 
10 5.50  (11.29) 0.520 0.242 104.1 
100 4.60  (25.80) 0.565 0.270 36.0 
1 O00 4.10  (33.87) 0.625 0.325 9.4 
- 
L.S.D. (1 '/O) 0.584 0.010 0.005 
L.S.D.  (5 '/O) 0.386 0.006 0.003 
O 5.70 - 0.365 0.178 
10 4.70  (17.54) 0.410 0.198 140.3 
100 3.60  (36.84) 0.455 0.220 49.9 
1 O00 3.00  (47.36) 0.500 0.268 10.9 
- 
L.S.D. (1 O/') 0.201 0.007 0.003 
L.S.D. (5 %) O. 133 0.004 0.002 
O 6.30 - 0.435 0.212 
10 
- 
5.55 (11.90) 0.503  0.237  108.8 
100  4.65 (26.19) 0.548  0.265  36.2 
1 O00 4.15 (34.12) 0.596  0.322  9.4 
L.S.D. (1 O/') 0.259  0.009 0.003 
L.S.D.  (5 ' /O) O. 170  0.006  0.002 
O 5.80 - 0.400  0.193
10  4.90  (15.51)  0.455  0.216 
- 
125.1 
100 3.80  (34.48) 0.500 0.240  43.6 
1 O00 3.30  (43. IO) 0.550 0.293  10.3 
L.S.D.  (1 '/O) 0.279  0.007  0.006 
L.S.D.  (5 '/O) 0.184  0.004  0.004 
Each value is a mean of five  replicates. 
In  parenthesis are  given per  cent reduction over  control. 
R = Reproduction  factor of the nematode, Pf = Final population, Pi = Initial Population, O.D. = O-dihydroxy  phenols. 
REFERENCES GIEBEL, J. (1974). Biochemical  mechanism  of  plant  resistance. 
A review. J. Nematol., 6 : 175-184. 
BIEHN, W. L., KUC, J. &WILLIAM, E. B. (1968). Accumulation JOHNSON, G. SCHAAL, L* (1954). RelationshiP of 
of  phenols  in  resistant  plant-fungi  nteractions. Phgo- genic  acid to the  scab  resistance  in  potatoes. Science, 115 : 
pathology, 58 : 1255-1260. 627-629. 
BRAY, H. G. & THORPE, W. V. (1954). Analysis of phenofic REBOIS, R. S., ELDRIDGE, B. P. &WEBB, R. E. (1977). Rotylen- 
compounds of interest  in  metabolism. Meth. Biochem.,Anal., chulus renijomzis parasitism of potato and its effect on 
1 : 27-52. yields. Pl. Dis. Repts; 62 : 520-523. 
Accepté pour  publication le 14 mai 1985. 
THE  POTENTIAL OF HIGH  RESOLUTION  VIDEO-ENHANCED  CONTRAST 
MICROSCOPY  IN  NEMATOLOGICAL  RESEARCH 
Urs Wyss and Ulrich ZUNKE* 
High power interference  contrast ciné-microscopy is tional  morphology (e.g. Robertson & Wyss, 1979; Sey- 
an  important tool for  studying  nematode  behaviour  and mour, 1983a, b). Video recordings  are very useful  for  an 
is, perhaps,  indispensable  for  detailed analysis of func- immediate analysis, provided the resolution is of suf- 
* Institut f i r  Phytopathologie der Christian-Albrechts-Universitat Kiel, Olshausenstr. 40, 0-2300 Kiel 1, W. Gennany. 
Revue Nématol. 9 (1) : 91-94 (1986) 91 


Relative susceptibility of different cultivars of tomato to Rotylenchulus reniformis in relation to changes in phenolics

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