Table of Contents
Dilday, R.H., P. Nastasi, R.J. Smith, Jr., and K. Khodayari. 1990.
Herbicide-tolerant germplasm in rice. p. 146-150. In: J. Janick and J.E.
Simon (eds.), Advances in new crops. Timber Press, Portland, OR.
Herbicide-tolerant Germplasm in Rice
R.H. Dilday, P. Nastasi, R.J. Smith, Jr., and K. Khodayari
- FIELD EXPERIMENTS
- LABORATORY EXPERIMENTS
- Table 1
- Table 2
- Fig. 1
Red rice (Oryza sativa L.) and cultivars of white rice belong to
the same genus and species (Hoagland and Paul 1978). Red rice is one of the
most common and troublesome weeds of rice in the southern U.S., causing an
estimated loss of $50 million dollars annually (Smith 1976). Red rice is a
problem weed because it has a red pericarp or seed coat which is commercially
unacceptable; reduces yield because it competes for light, nutrients, and
space; tillers more profusely; increases lodging because of its weak straw;
reduces milling yield because it requires more severe milling to remove the red
pericarp; and shatters easily which makes it hard to eliminate from commercial
fields (Dodson 1898; Nelson 1979; Smith 1981). Control of red rice in
commercial rice fields is economically prohibitive and selective herbicides for
control of red rice in rice are not available.
Strawhull and blackhull are the two principal types of red rice. Chemical
control of red rice in commercial fields has not been achieved because of the
similar biological and physiological properties of red and commercial rice.
However, rice rotated with upland crops combined with effective herbicides will
control red rice (Baker and Sonnier 1983; Smith 1976, 1979). Soybeans grown
for two years and followed by rice the third year has reduced red rice
infestations sufficiently for satisfactory rice production (Smith 1979).
Alachlor, which is absorbed by germinating seeds, controls red rice in soybeans
(Khodayari et al. 1987).
The development of rice cultivars which are tolerant to a herbicide that
controls red rice would help control red rice in commercial rice.
Intraspecific variation in tolerance to herbicides has occurred in crops such
as barley (Hordeum vulgare L.) (Derscheid et al. 1952); oats (Avena
sativa L.) (Smith and Buchholtz 1964, Williams 1953); corn (Zea mays
L.) (Williams 1953, Wright and Rieck 1973, 1974); sorghum [Sorghum
bicolor (L.) Monech] (Scifres and Bovey 1970); sugarcane (Saccharum
officinarum L.) (Matherne and Millhollon 1973, Millhollon and Matherne
1968); soybeans [Glycine max (L.) Merr.] (Barrentine et al. 1982, Hays
and Wax 1975, Wax et al. 1974, Williams 1953); potato (Solanum tuberosum
L.) (Graf and Ogg 1976); and tomato (Lycopersicon esculentum Mill.)
(Stephenson et al. 1976). Rice cultivars and advanced lines that are tolerant
to molinate, an herbicide which controls barnyardgrass, have been identified
(Richard and Baker 1979, Smith 1970).
The objectives of this study were to develop field and laboratory techniques
for evaluating rice germplasm for resistance to alachlor and evaluate
accessions from the rice portion of the USDA/ARS small grains germplasm
collection for tolerance to alachlor.
Six experiments involving two concentrations of alachlor and 4,567 accessions
from the rice portion of the USDA/ARS small grains collection were conducted
from 1983 to 1985 near the Rice Research and Extension Center, Stuttgart,
Arkansas. The tests were drill seeded (3 g of seed/m) in single row plots 1.23
m long with a 19 cm row spacing in two replications on June 1-2, 1983; June
10-12, 1984; and May 23-25, 1985. Prior to seeding, 4.58 and 6.88 kg ai/ha of
alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide] was
incorporated to a depth of 5 to 8 cm into a Crowley silt loam, a fine
montmorillonite thermic Typic Albaqualf. Plant height and grain type were
determined at maturity. Two replicated tests were conducted in 1986. Each
test included 2 row plots 1.23 m long with each row being 19 cm apart and the
tests were treated with 4.58 and 6.88 kg ai/ha of alachlor. The experimental
design for this test was a randomized complete block with four replications.
The total number of seedlings that emerged were determined 7, 14 and 21 days
after seeding in each test.
The 4,567 rice accessions that were evaluated for tolerance to alachlor
originated in 34 countries. Sixteen accessions that had a higher level of
tolerance to alachlor than the others originated in Pakistan, India, Sierra
Leone, Madagascar, Sri Lanka and Philippines. Furthermore, eight of the 16
accessions came from an area along the Pakistan and India border, three from
the Philippines, two from Africa (Sierra Leone), two from Islands in the Indian
Ocean (Madagascar and Sri Lanka), and one unknown (Table 1). The accessions
included short, medium, and long grain types that produced plant heights
ranging from 90 to 157 cm. Based on results from field trials and laboratory
tests, the 16 accessions were evaluated further in the field in 1986. Seedling
emergence was significantly greater for two accessions, 'IR 1317-152' and
' Jhona White Pak 83', than for the other 14 accessions or the two checks.
IR 1317-152 is identified as PI 349393 in the rice portion of the USDA/ARS
small grains collection that is maintained at Aberdeen, Idaho. IR 1317-152
originated at the International Rice Research Institute, Los Banos, Philippines
and its identifying plant characteristics are: medium grain, semidwarf plant
that requires between 100 to 110 days to develop from seedling emergence until
50% of the main tillers show panicles, culm or culm angle is open, panicle type
is intermediate, hull completely covered with short hairs or pubescence, straw
colored hull and sterile lemma, partly awned with long awns, light brown seed
coat (bran/pericarp) color and lodging resistance is moderately strong. 'Jhona
White Pak 83', identified as PI 385565 in the rice collection, originated in
Pakistan and its identifying plant characteristics are: long grain, tall plant
that requires between 90 to 100 days to develop from seedling emergence until
50% of the main tillers show panicles, culm or culm angle is open, panicle type
is intermediate, hull completely covered with short hairs or pubescence, straw
colored hull and sterile lemma, awns are absent, light brown seed coat, and
lodging resistance is very weak. The definition of each plant characteristic
is based on the IBPGR-IRRI Rice Advisory Committees report on "Descriptors for
Rice Oryza sativa L." (IBPGR-IRRI Committee 1980).
In 1985 five seeds per accession from a total of 180 accessions and two checks,
'Lemont' and 'Lebonnet', were germinated in disposable petri dishes which
contained Whatman's No. 1 filter paper, moistened with 3 ml of 2 and 3 ppmw of
alachlor. The mesocotyl and coleoptile were measured after the petri dishes
were placed in a temperature controlled germination chamber for seven days at
28°C. Abnormal or diseased seedlings were determined for percent
germination but the mesocotyl and coleoptile lengths were not measured because
of abnormal growth and development of these seedlings. Each seed was
considered germinated when the mesocotyl-coleoptile developed to a length of 2
mm. The seedlings which produced leaves were washed in water and transplanted
in herbicide-free soil in pots in the greenhouse for 3 weeks to observe their
growth and development. In 1986, 16 of the most tolerant accessions and 2
checks (Lemont and Lebonnet) were evaluated in a germination chamber at 28°C
for 7 days on Whatman's No. 1 filter paper, moistened with 3 ml of 0 (check),
0.1, 0.5,1.0, 3.0, 5.0, and 10.00 ppmw of alachlor. After 7 days the mesocotyl
coleoptile, primary leaf, secondary roots, and radicle of each seedling were
measured. Each laboratory test was replicated 6 times.
Alachlor is absorbed primarily through the mesocotyl and coleoptile tissue of
the seedling and ultimately disrupts the development of the radicle, secondary
roots, and primary leaves (Pillai et al. 1979). Furthermore, the elongation
potential of the mesocotyl and coleoptile is heritable and varies according to
the genetic constitution of the germplasm (Dilday et al. 1988). Inge and
Loomis (1937) demonstrated that mesocotyl elongation is inhibited when the tip
of the coleoptile is exposed to light. Also, the elongation of the mesocotyl
and coleoptile is influenced by the depth of seeding (Fig. 1).
Results from the laboratory experiments demonstrated that the
mesocotyl/coleoptile elongation was reduced by about 50% in 'Lemont',
'Lebonnet', and IR 1317-152 at 0.1 ppm (by weight); whereas, 1 0.0 ppm not
inhibit mesocotyl/coleoptile elongation by 50% in Jhona White Pak 83 (Table 2).
Secondary root development of the checks, Lemont and Lebonnet, did not occur
even at the lowest concentration of 0.1 ppm. Secondary root development of
Jhona White Pak 83 occurred up to 3.0 ppm. Furthermore, secondary root
development of IR 1317-152 occurred at the highest concentration of 10.0 ppm.
Primary leaf development was not initiated in either check at 0.1 ppm; however,
it did occur at 0.1 and 0.5 ppm in Jhona White Pak 83. Primary leaf
development continued to occur at the highest concentration (10.0 ppm) in IR
1317-152. The development of the radicle was reduced by 50% or more in the two
check cultivars at the lowest concentration (0.1 ppm) of alachlor, however, a
50% or greater reduction in the development of the radicle did not occur until
treated at the 0.5 ppm alachlor concentration for both tolerant germplasm
The two tolerant germplasm accessions responded differently to alachlor which
suggests that the tolerance is due to separate genetic mechanisms. For
example, the mesocotyl-coleoptile development of the two cultivars and IR
1317-152 was similar when grown in alachlor; whereas, there was no significant
difference in mesocotyl/coleoptile development of Jhona White Pak 83 to
alachlor at the 0.1 and 0.5 ppmw concentration. Conversely, the leaf and
secondary root development of IR 1317-152 was more tolerant to alachlor when
compared with Jhona White Pak 83. The development of the radical of the two
tolerant germplasm accessions grew similarly in alachlor. This suggests that
pyramiding of tolerant genes from different germplasm sources such as IR
1317-152 and Jhona White Pak 83 could increase the overall level of germplasm
tolerance to alachlor.
Red rice causes an estimated loss of $50 million dollars annually in commercial
rice in the southern U.S. because there is not an economical method of
controlling red rice in commercial rice. The concept of developing and
utilizing herbicide-tolerant cultivars in a red rice control program could be a
very practical approach for control of this weed.
- Baker, J.B. and E.A. Sonnier. 1983. Red rice and its control, p. 327-333. In
Weed control in rice. Proc. Conf. Int. Rice Res. Inst., Los Banos, Laguna,
- Barrentine, W.L., E.E. Hartwig, C.J. Edwards, Jr., and T.C. Kilen. 1982.
Tolerance of three soybean (Glycine max) cultivars to metribuzin. Weed
- Derscheid, L.A., L.M. Stahler, and D.E. Kratochvil. 1952. Differential
responses of barley varieties to 2,4-dichloro-phenoxy-acetic acid (2,4-D).
Agron. J. 44:182-188.
- Dilday, R.H., S.L. Skinner, M.A. Mgonja, and F.C. Collins. 1988 Association of
mesocotyl and coleoptile elongation with seedling vigor in rice. Arkansas Acad.
Sci. 41: 36-39.
- Dodson, W.R. 1898. Red rice. Louisiana Agric. Exp. Stn. Bul. 50:206-226.
- Graf, G.T. and A.G. Ogg, Jr. 1976. Differential response of potato cultivars to
metribuzin. Weed Sci. 24:137-139.
- Hayes, R.M. and L.M. Wax. 1975. Differential interspecific responses of soybean
cultivars to bentazon. Weed Sci. 23:516-522.
- Hoagland, R.E. and R.N. Paul. 1978. A comparative SEM study of red rice and
several commercial rice (Oryza sativa L.) varieties. Weed Sci.
- IBPGR-IRRI Rice Advisory Committee. 1980. Descriptors for rice Oryza
sativa L. Intern. Rice Res. Inst., Los Banos, Laguna, Philippines.
- Inge, R.D. and W.E. Loomis. 1937. Growth of the first internode of the epicotyl
in maize seedlings. Am. J. Bot. 24:542-547.
- Khodayari, K., R.J. Smith, Jr, and H. Black. 1987. Red rice (Oryza
sativa L.) control with herbicide treatments in soybeans (Glycine
max). Weed Sci. 35:127-129.
- Matherne, R.J. and R.W. Millhollon. 1973. Tolerance of two sugarcane cultivars
to terbacil, fenac, and dalapon. Weed Sci. 21:139-140.
- Millhollon, R.W. and R.H. Matherne. 1968. Tolerances of sugarcane varieties to
herbicides. Weed Sci. 16:300-303.
- Nelson, R.J. 1979. Rice culture. Arkansas Agric. Expt Sta. Bull. 94:31-45.
- Pillai, P., D.E. Davis, and B. Truelove. 1979. Effects of metalachlor on
germination, growth, leucine uptake, and protein synthesis. Weed Sci.
- Richard, E.P., Jr. and J.B. Baker. 1979. Response of selected rice (Oryza
sativa L.) lines to molinate. Weed Sci. 27:219-223.
- Scifres, C.J. and R.W. Bovey. 1970. Differential responses of sorghum varieties
to picloram. Agron. J. 62:775-777.
- Smith, D. and K.P. Buchholtz. 1964. Oat variety responses to triazine
herbicides. Crop Sci. 4:223-225.
- Smith, R.J., Jr. 1970. Molinate for barnyardgrass control in rice. Weed Sci.
- Smith, R.J., Jr. 1976. Crop and herbicide systems for red rice control in rice.
Proc. South. Weed. Sci. Soc. 29:164.
- Smith, R.J., Jr. 1979. How to control the hard-to-kill weeds in rice. Weeds
- Smith, R.J., Jr. 1981. Control of red rice (Oryza sativa) in
water-seeded rice (O. sativa). Weed Sci. 29:663-666.
- Stephenson, G.R., J.E. McLeod, and S.C. Phatak. 1976. Differential tolerance of
tomato cultivars to metribuszin. Weed Sci, 24:162-265.
- Wax. L.M., R.L. Bernard, and R.M. Hayes. 1974. Response of soybean cultivars to
bentazon, bromoxynil, chloroxuron, and 2,4-DB. Weed Sci. 22:35-41.
- Williams, J.H. 1953. Differential varietal response of root tissue to exogenous
growth regulators in soybeans, oats, and corn. Agron. J. 45:293-297.
- Wright, T.H. and C.E. Rieck. 1973. Differential butyrate injury to corn
hybrids. Weed Sci. 21:194-196.
- Wright, T.H. and C.E. Rieck. 1974. Factors affecting butylate injury to corn.
Weed Sci. 22:83-86.
Table 1. Origin, plant height, grain type, and number of emerged
seedling/m of 16 germplasm accession and two cultivar checks that varied in
tolerance to alachlor (4.58 kg/ha).
zM = Medium grain; MX = Mixed grain; L = Long grain; S = Short grain.
|Germplasm identification ||Country of origin || Plant height (cm) ||Grain typez ||No. emerged seedlings/m|
|ARC 10311 ||India ||157 ||M || 9.0ay|
|IR-1317-152 ||Philippines ||91 ||M || 8.5a|
|Jhona White Pak 83 ||Pakistan ||146 ||L ||8.2a|
|ARC 10105 ||India ||155 ||M ||4.4b|
|IR-1317-386 ||Philippines ||90 ||M ||4.0bc|
|PI 433811 ||Sierra Leone ||119 ||MX ||3.5bcd|
|Early Prolific Sel 388 ||Unknown ||109 || M ||3.5bcd|
|PI 461222 ||Sierra Leone ||115 ||MX ||3.2cd|
|IR-527-1-57 ||Philippines ||93 ||M ||3.1cd|
|Coarse Pak 76S ||Pakistan ||142 ||M ||2.5de|
|Jhona Sufaio Pak 67 ||Pakistan ||123 ||L ||1.8ef|
|Madagascar 1300 ||Madagascar ||144 ||S ||1.6ef|
|BG 34-8-Ceylon ||SRI Lanka ||102 ||S ||1.6ef|
|ARC 10757 ||India ||133 ||L || 1.5ef|
|Siah Nakidar Pak 195 ||Pakistan ||131 || L ||1.4f|
|ARC 10583 ||India ||168 ||M || 1.2f|
|LMNT ||U.S. ||85 ||L ||0g|
|LBNT ||U.S. ||109 ||L ||.0g|
yMean separation by Duncan's multiple range test, 5% level of probability
Table 2. Response of 2 cultivars without tolerance and 2 germplasm
accessions with tolerance to Alachlor.
zMeans separation in columns by Duncan's multiple range test, 5% level of
|Alachlor rate (ppmw) ||Lemont ||Lebonnet ||IR-1317-152 ||Jhona White Pak 83z|
| ||Mesocotyl/Coleoptile length (cm)|
|0 ||1.1a ||1.7a ||1.9a ||0.8ab|
|0.1 ||0.6bc ||0.8b ||1.0b ||0.9a|
|0.5 ||0.4cd ||0.6bc ||1.0b ||0.8ab|
|1.0 ||0.4cd ||0.4cd ||0.8bc ||0.6b|
|3.0 ||0.4cd ||0.4cd ||0.8bc ||0.6b|
|5.0 ||0.4cd ||0.4cd ||0.7c ||0.6b|
|10.0 ||0.3d ||0.2d ||0.7c ||0.5b|
| ||Length of secondary root(cm)|
|0 ||0.4 ||1.2 ||0.7a ||1.0a|
|0.1 ||0.0 ||0.0 ||0.7a ||0.6b|
|0.5 ||0.0 ||0.0 ||0.3b ||0.2c|
|1.0 ||0.0 ||0.0 ||0.4b ||0.1c|
|3.0 ||0.0 ||0.0 ||0.4b ||0.0|
|5.0 ||0.0 ||0.0 ||0.2c ||0.0|
|10.0 ||0.0 ||0.0 ||0.2c ||0.0|
| ||Length of primary leaf(cm)|
|0 ||1.1 ||2.3 ||3.2a ||1.6a|
|0.1 ||0.0 ||0.0 ||0.4b ||1.6a|
|0.5 ||0.0 ||0.0 ||0.2bc ||0.2b|
|1.0 ||0.0 ||0.0 ||0.2bc ||0.0|
|3.0 ||0.0 ||0.0 ||0.1c ||0.0|
|5.0 ||0.0 ||0.0 ||0.1C ||0.0|
|10.0 ||0.0 ||0.0 ||0.1C ||0.0|
| ||Radicle length (cm)|
|0 ||3.6a 4.9a ||3.7a ||5.4a|
|0.1 ||1.8b ||1.7b ||3.2a ||5.2a|
|0.5 ||1.1c ||1.4b ||1.7b ||1.2bc|
|1.0 ||0.9c ||1.2bc ||1.3bc ||1.7b|
|3.0 ||1.1c ||0.7cd ||1.3bc ||1.3bc|
|5.0 ||0.8cd ||0.8cd ||0.8c ||1.5bc|
|10.0 ||0.3d ||0.5d ||0.8c ||1.0c|
Fig. 1. Schematic of rice seedlings showing the major seedling
components and demonstrating how seeding depth influences mesocotyl/coleoptile
Last update August 26, 1997