rice in the united states: varieties and production

126 Pages·2010·11.11 MB·English

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RICE IN THE UNITED STATES:
VARIETIES AND PRODUCTION
Agriculture Handbook No. 289
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■
Agricultural Research Service
U.S. DEPARTMENT OF AGRICULTURE
RICE IN THE UNITED STATES:
VARIETIES AND PRODUCTION
l/4epé4á^í¿aled^aff¿^
POI-LOW THE LABEL
u s. eeritiMiNT OF A&IKULTUIE
Agriculture Handbook No. 289
Agricultural Research Service
U.S. DEPARTMENT OF AGRICULTURE
IsHued 196«
Washington, D.C.
For sole by the Superintendent of Documents. U.S. Government Printing Office. Washington. D.C. 20402 Price .$1.
CONTRIBUTORS
C. ROY ADAIR, leader, Rice Investigations, Crops Research T. H. JOHNSTON, research agronomist, Crops Research
Division, Agricultural Research Service, Beltsville, Division, Agricultural Research Service, Stuttgart
Md. Ark.
J. G. ATKINS, plant pathologist. Crops Research Division, D. S. IMiKKELSEN, associate agronomist. University of
Agricultural Research Service, Beaumont. Tex. California, Davis, ('alif.
H. M. BEACHELL, formerly, researcli agronomist, (^rops M. D. MILLER, assistant state director, Agricultural Ex-
Research Division, Agricultural Research Service.
tension Service, University of California, Davis,
Beaumont, Tex. ; now, plant breeder. Varietal Im-
Calif.
provement Department, International Rice Research
W. C. SHAW, formerly, leader. Weed Investigations in
Institute, Los Banos, Philippines.
Agronomic Crops, Crops Research L)ivision, Agricul-
N. S. EvATT, associate agronomist, Rice-Pasture Research
tural Research Service, Beltsville, Md. ; now, interde-
and Extension Center, Texas Agricultural Experi-
partmental pesticides coordinator, U.S. Department
ment Station, Beaumont, Tex.
T. R. EVERETT, formerly, leader. Rice Insects Investiga- of Agriculture, Washington, D.C.
tions, Entomolog^^ Researcli Division, Agricultural R. J. SMITH, JR., research agronomist, Crops Research
Research Service, Baton Rouge, La. : now, associate Division, Agricultural Research Service, Stuttgart,
professor, Louisiana State Universitv. Baton Rouire Ark.
La. J. R. THYSELL, formerly, research agronomist, Crops Re-
V. E. GREEN. JR., associate agronomist, p]verglades Ex- search Division, Agricultural Research Service, Biggs,
periment Station, Florida Agricultural Experiment <'alif. ; now, agronomist. Crops Research Division,
Station, Belle Glade, Fla. Agricultural Research Service, Brookings, S. Dak,
NELSON E. JODON, research agronomist. Crops Research B. D. WEBB, research chemist. Crops Research Division,
Division, Agricultural Research Service. Crowlev. La. Agricultural Research Service, Beaumont, Tex.
Trade names are used in this publication solely for the purpose of providing specific information.
Mention of a trade name does not constitute a guarantee or warranty of the product by the U.S.
Department of Agriculture or an endorsement by the Department over other products not mentioned.
CONTENTS
Introduction 1
Fertilizers 69
History of rice in the United States 1 Southern rice area 69
Distribution of rice in the United States 3 California 71
Acreage, yield, and production of rice in the Selected references 72
United States 3 Culture 74
Selected references 4 Rotation or cropping systems 74
Distribution and origin of species, botany, and Arkansas 75
genetics 5 Louisiana 76
Distribution of the species of Oryza and origin Mississippi 77
of cultivated rice 5 Missouri 78
Description and development of the rice plant Texas 78
and classification of cultivated varieties 6 California 79
Description of plant 7 Land leveling and seedbed preparation 79
Development of plant 8 Land grading and leveling 79
Classification of varieties 9 Seedbed preparation 81
Genetics 9 Seedbed preparation as related to method
Selected references 16 of seeding 82
Rice breeding and testing methods in the United Construction of levees 83
States 19 Seed and seeding 84
History and objectives 19 Seed quality 84
Cultural methods and equipment for breeding Source of seed 85
rice in the United States 20 Seed treatment 85
Breeding methods 24 Time of seeding 86
Introduction 24 Rate of seeding 87
Selection 25 Method of seeding 88
Hybridization 25 Transplanting rice 91
Irradiation 28 Irrigating and draining 91
Breeding for agronomic characters 28 Amount of water required 92
Testing for milling, cooking, and processing Source of water 92
qualities 33 Quality of water 93
Milling quality 33 Water temperature and oxygen content 94
Cooking and processing qualities 35 Water control methods 95
Breeding for disease resistance 38 Water management 97
Blast 39 Draining for harvest 99
Brown leaf spot 39 Harvesting, drying, and storing 99
Narrow brown leaf spot 40 Harvesting 99
Straighthead 40 Drying and storing 103
White tip 40 Selected references 106
Hoja blanca 40 Weeds and their control 111
Description of varieties 42 Rice diseases 113
Short-grain varieties 42 Major diseases 113
Medium-.grain varieties 44
Blast 113
Long-grain varieties 45 Brown leaf spot 114
Other kinds of rice 47
Narrow brown leaf spot 114
Performance of varieties 47
Root rot 115
Choosing the variety 49
Seedling blight 116
Varietal response to seeding date 51
Stem rot 116
Results of tests with older varieties 51
Straighthead 117
Results of tests with newer varieties and
White tip 117
selections 52
Minor diseases 118
Production of seed rice 56
Bordered sheath spot 118
Origin of high-quality seed rice 50
Hoja blanca 118
Classes of seed in a certification program, 56
Kernel smut 119
Cleaning, grading, and processing seed rice 59
Kernel spots 119
Standards for seed certification 61
Leaf smut 119
Selected references 62
Selected references 120
Soils and fertilizers 65
Insects and their control 121
Types of soils used for rice production 65
Rice water weevil 121
Arkansas 65
Louisiana 65 Rice stink bug 121
Texas 65 Grape colaspis 122
California 65 Other pests of rice 122
Chemistry of flooded soils 67 Selected references 124
111
RICE IN THE UNITED STATES: VARIETIES AND PRODUCTION
INTRODUCTION
By C. ROY ADAIK
Eice, a leading cereal crop in many countries, ond i o Ri'azil in the AVestern Hemisphere. Other
is grown on all continents. It often is considered leading rice-producing countries, outside of Asia
to be a tropical crop, although it is grown in both
and adjacent islands, are United Arab Republic
the temperate and the tropical zones in Africa,
(Egypt) and Malagasy Republic (Madagascar)
Asia, Xorth America, Oceania, and South Amer-
in Africa, and Italy and Spain in Europe.
ica, and in the southern part of Europe. About
Rice yields yary widely among the rice-produc-
93 percent of the world rice crop was produced
ing countries (table 1). Yields generally are
in Asia during the 5-year period ending in 19(30
(table 1). Only slightly more than 1 percent was nnich liigher in temperate than in tropical
produced in the United States during this period. zones, not only because of diiferences in climate
The United States is, howeyer, the leading rice- but also because of differences in cultural prac-
producing country in North America and is sec- tices and in yarieties grown.
TABLE 1.—Rice- acreage, production, and yield' per arre for each continent and selected' countries,
averages for 5-year period. 1956-60
Continent and country Acreafre Production Yield
1,000 acres Million pounds Pounds per acre
Asia 258,000.4 427,330.2 1,656
India 81,353.2 99,106.7 1,218
Japan 8,050.2 32,845.4 4,081
South America 8,091.6 12,496.2 1,544
Brazil 0,615.0 9,539.7 1,442
P»^ru - - 166.4 574.4 3,452
Africa 7,808.0 9,686.0 1,240
Coníío 400.0 392.C 982
United Arab RepubUo (Etiypt) 095.4 2,832.4 4,073
North America 2,825.0 6,985.3 2,473
Mexico 315.0 582.0 1,844
TTnited States 1,501.8 4,946.2 3,294
Eurooe 860.6 3.434.8 3,991
Italy 325.6 1,440.3 4,423
Spain 157.0 841.7 5,341
Oceania 117.2 330.9 2,823
Australia 50.2 240.7 4,795
World total 277,702.8 460,263.4 1,657
Source: U.S. Department of Agriculture, Agricultural Statistics: 1958, p. 21; 1959, p. 1960. p. 1961, p. 22.
History of Rice in the United States made in the prairie section of southwest Louisiana
from 1884 to 1886 (7), and rice culture became
Rice has been grown in the United States since established in that area about 1888. Production
the latter part of the 17th century {;3)} Trial then increased rapidly in that part of Louisiana,
plantings of rice were made in Virginia as early and in the adjacent part of Texas. Some rice was
as 1609 (4). Apparently other plantings were grown along riyers in Arkansas in early years,
made in the colonies along the South Atlantic but it did not become an important cash crop in
coast from that time on, and ricegrowing was the State until after 1904 (P), when ricegrowing
firmly established in South Carolina about 1090. was started in Grand Prairie. Experimental
Until about 1890, rice in the United States was plantings were made near Butte Creek in the Sac-
grown principally in the Southeastern States, al- ramento Valley in California in 1909 (5), and
though some was grown along riyers in the South rice became established as a commercial crop in
Central States. Experimental plantings were that area about 1912. Rice production has been
of considerable importance in the delta area of
1 Italic numbers in parentheses refer to Selected Ref-
Mississippi since about 1948 (2).
erences, p. 4.
AGRlCLíLTURE HANDBOOK 2 89, tl.S. DEPT. OF A(iRI(!ULïURE
ARKANSAS
ARKANSAS CONT.
CALIFORNIA
LOUISIANA
SECTION AND ACRES
SOUTHWEST
SECTION AND
SECTION AND
ACRES
ACRES
COUNTY
Lo f a y e 11 e COUNTY
PARISH
Linie River
NORTHEAST .... 2,000
SACRAMENTO VALLEY
NORTH
Miller
Clay 7,770
Butle 55,202
Eost Corroll* -•5,267
Croigbeod 16,935
TOTAL ACRES...
Coluso 74,125
Grant
••••185
430,061
■
Crittenden 6,439
ARKANSAS 1963
Glenn 40,846
Madison
•••896
Cross 34,060
Placer 3,050
Morehouse.*..
5,949
Faulkner 318
TEXAS
Sacramento 10,126
West Carroll •
• 1,185
Greene 5,406
SECTION AND
ACRES
Suiter 57,789
Independence 852
COUNTY
Yolo 25,062
RIVER
Jackson 20,200
EAST
Yubo 12,549
Ascension-^'
•1,316
Lawrence g 251
.... 559
Assumption -
SAN JOAQUÍN VALLEY
•••196
Mississippi 1,505
Chambers "
•43,503 Iberville
• 323
■
Fresno 20,818
Poinsell 38,400
Ho r d i n .... 54
Kern
•- 1,004
Lafourcfie -••
Randolph 2,100
-• 3,435
Kings
Jasper
St. j om es •••
86 •1,472
197
St. froncis 17,840
Modero
Jefferson ••
St. John •••-
1,436
62,294
■
While 1,140
••2,745
■
Merced
Liberty
Tensos
37,540
•• 126
•• 7,429
Woodruff 19,760
Newton Son Joaquin*
731
•• 7,453
TECHE
Stanislaus-..
Oronge
CENTRAL
-• 4,972
•• 2,260
.... 544
Tulare
Avoy elles.
Arkansas 76,150
CENTRAL
2,770
Iberio
Clork 400
6,500
Br az 0 r ia• "
TOTAL ACRES
-54,003
323,630
Con wo y 114 Lafayette-
• 9,530
Ft. Bend"--
CALIFORNIA 1963
19,203
R 0 p i d e s • • • •
^la' Spring 4 70
•••574
GaI ves f 0 n "
• 12,143
iSSISSIPPI
Harris St. Martin-
Jefferson 17,04 6
4,060
■
34,889
Waller St. Mory-^^
• 3,100
L" 8,395
15,038
■
COUNTY
ACRES
' ""f^e 39,000
■
WEST
Bolivar
""airoc 14,000
SOUTHWEST
Austin
,400
-.2,865
Acodia
Coohoma ' 93,500
''^"y 981
664
Co 1 h ou n -'•'
•••4,287
Allen
''''illips 5,068 •24,000
■
De Soto
639
Colorado •--
•35,599
'''"'"'le 39,570 Beauregord •••*
•• 4,943
Hancock
184
Jackson •••-
• 27,153
Puloski 1,855
•65,088
Colcasieu
Humphreys
935
Lavaco
•••6,194
Cameron •13,337
Leflore
874
SOUTHEAST
Ma t ag 0 r d 0 -
•44,846
Evan geline
• 39,640
Quitmon
408
Ashley 6,429
Victorio
•• 5,083
Jeffe r son Da vi
-95,692
S horkey
,150
Whar Ion-...
'^'''"' 9,603
-52,740
St. Londry 16,945
Sunflower
300
?,= ^*'a 14,000
Vcrmillion 114,800
Tallohotche
510
""''" 4,594
TOTAL ACRES
Täte
Lincoln 9,410
246
•464,732
TEXAS 1963 '
TOTAL ACRES 5,2,884
Tunica
895
LOUISIANA 1963
Washington
427
TOTAL ACRES
50,632
MISSISSIPPI 196'3'
FluUKE 1.—:
Distribution of the United States rice acreage in the principal producing States.
RICE IN THE UNITED STATES : VARIETIES AND PRODUCTION
Distribution of Rice in the United States 2,250
Although rice is probably the leading food
crop of the world, it is a major crop in the United 2,000
States in certain areas only. Rice production in
the United States is centered in the Southern
,750
States of Arkansas, Louisiana, Mississippi, and
Texas and in California. It is the principal cash
crop in many counties and parishes (fig. 1). 1,500 -
Small amounts of rice also are grown in Missouri,
Oklahoma, South Carolina, and Tennessee. Some
1,250
rice has been grown in each of the States in
Southeastern United States.
In the United States, satisfactory rice crops 1,000
require (1) high temperature, especially rela-
tively high mean temperatures during the grow-
ing season; (2) a dependable supply of fresh 750
water for irrigation; (3) a terrain that is level
enough to permit flood irrigation but that slopes
500
enough so that surface water can be readily
drained; and (4) soil that will hold water well
because of its fine texture, or a subsoil through 250
which loss by seepage is small (6). These cli-
matic and soil conditions prevail in the areas
where rice is grown in the United States.
Rainfall and humidity during the growing sea-
son are comparatively high in the Southern
FIGURE 2.—Harvested acreage of rice in the United
States, so less irrigation water is required there
States (5-year annual moving average), 1899-1963.
than in California (i). Irrigation water is sup-
plied from streams, from reservoirs where water
is impounded in winter and early spring, and moving average acreage increased each year until
from wells. To produce optimum yields, proper 1955, when it was 2,106,000. The peak acreage of
cultural practices must be followed. These prac- 2,550,000 was reached in 1954. The annual acre-
tices include preparing a suitable seedbed, main- age then declined until 1957, when it was
taining a uniform depth of irrigation water, 1,340,000. Starting in 1958, acreage increased
providing sufficient soil nutrients for optimum slightly each year until 1963, when it was
growth, and controlling insects and diseases and 1,765,000.
weeds and grasses. Good-quality seed of adapted Yield per acre (fig. 3) in the United States in-
varieties must be used to maintain quality and to creased from a 5-year annual moving average of
produce high economical yields. For safe stor- 1,091 pounds per acre in 1899 to 3,563 pounds per
age, the rice must be harvested at the right stage acre in 1963. This gradual increase in yield per
and dried to the proper moisture level. acre has been brought about by improved cultural
practices, such as better rotations, weed control,
Acreage, Yield, and Production of Rice and irrigation and fertilization practices; better
in the United States machinery, which led to improved and more time-
In the 5-year period ending in 1963, Arkansas ly field operations; better methods of controlling
produced 2Í.89 percent of the total United States diseases and insects; and improved varieties.
rice crop; Louisiana, 24.26 percent; California, Average yields have fluctuated from year to year,
24.12 percent; Texas, 23.99 percent; Mississippi, with a long-term upward trend. However, there
2.47 percent ; and Missouri, 0.26 percent (S). The have been short periods when average yields de-
United States has been self-sufficient in rice pro- clined. The 5-year annual moving average yield
duction since 1917, and now is one of the leading per acre increased gradually from 1899 to 1940,
rice-exporting countries of the world. but six times during this period the 5-year aver-
Rice acreage in the United States (fig. 2) in- age yield was lower than that of the previous
creased from a 5-year annual moving average of year. Yields declined from 1941 to 1945. Labor
301,000 acres in 1899 to 1,105,000 acres in 1922. and equipment were scarce during the war years,
It then declined imtil 1936. The 5-year annual and the acreage was expanded to include some
AGRICULTTTRE IIxVNDBOOK 2 8 9, U.S. DEPT. OF AGRICULTURE
production was 69.3 million bags, and the 5-year
annual moving average was 59.3 million bapfs
3,500 (fig. 4).
Selected References
3,000
(1; ADAIK, C. R., and ENGLER, KYLE.
1955. THE IRRIGATION AND CULTURE OF RICE. lu
Water, U.S. Dept. Agr. Yearbook of Agr
pp. 380-394.
5 2,500
(2) MILLER, M. D., and BEACHELL, H. M.
1962. RICE IMPROVEMENT AND CULTURE IN THE
UNITED STATES. Adv. in A^roD. 14: 61-108.
(3) CHAMBLISS, C. E.
1912. A PRETJíMINARY REPORT ON RICE GROWING IN
2,000
THE SACRAMENTO VALLEY. U.S. Dept, Agr
Bur. Plant Indus. Cir. 97, 10 pp.
(4) GRAY, L. C, and THOMPSON, E. K.
1941. HISTORY OF AGRICULTURE IN THE SOUTHERN
U.S. TO 1860. Carnegie Inst. Wash. Pub.
5 1,500
430. [Reprinted in 2 v.] Peter Smith,
New York.
(5) HOLMES, G. K.
1912. RICE CROP OF THE UNITED STATES, 1712-1911.
U.S. Dept. Agr., Bur. Statis. Cir. 34, 11 pp.
1,000 -
(6) JONES, J. W., DOCKINS, J. O., WALKER, R. K., and
DAVIS, W. C.
1952. RICE PRODUCTION IN THE SOUTHERN STATES.
U.S. Dept. Agr. Farmers' Bui. 2043, 36 pp.
( 7) KNAPP, S. A.
1899 1929 1939 969 1899. THE PRESENT STATUS OF RICE CULTURE IN
YEAR THE UNITED STATES. U.S. Dept. Agr., Bot.
Div. Bui. 22, 56 pp.
FIGURE 3.—Yield per acre of rice in the United States ( 8 ) UNITED STATES DEPARTMENT OF AGRICULTURE.
(5-year annual moving average), 1S£M;^1963. 1968. RICE. ANNUAL MARKET SUMMARY, Yô^J.
U.S. Agr. Market. Serv. AMS-277, 47 pp.
(9) ViNCENHELLER, W. G.
1906. RICE GROWING IN ARKANSAS. Ark. Agr.
Expt. Sta. Bui. 89, pp. 119-129.
fields with p(X)r soil. These factors may have
accounted for the lower yields in this periocl. The
5-year average yield per acre increased each year
from 1946 through 1963. Higher rates of fertil-
izer application and other improved cultural
practices increased yields during this period.
Production of rice (100-pound bags) in the
United States in I7l8 was estimated to be over
79,000 bags of rough rice (J). Production in-
creased to nearly 3.5 million bai^s in 1849. It
then declined to about 637,000 bags by 1871. By
1899, production had increased to ^3.4 million
bags.
The 5-year annual production increased to 19.4
million bags in 1922. Production declined until
1926 and then increased slightly. However, it
remained within the range of Í4 to 20 million
bags until 1936. The annual production fluctu-
ated from year to vear but with an upward trend
during the period from 1937 to 1954 when pro-
duction reached a high of 64.2 million bags.
Annual production declined until 1958 and then
mcreased each year until 1963 when the annual KTGT RF 4.—Production of rice in the United States
(5-year annual moving average), 1899-1963.
DISTRIBUTION AND ORIGIN OF SPECIES, BOTANY, AND GENETICS
By C. ROY ADATR and NELSON E. JODON
Distribution of the Species of Oryza Tateoka (6'4) are listed in table 2.
and Origin of Cultivated Rice Five species were reco^iized by Chatterjee [13)
but not by Tateoka {6^ so they were not listed
Species of Ori/sa have been reported from all in table 2. These are O. granulata Nees & Arn.
continents except Europe and from many of the ex Hook, f.; 0. pereyinis Moench; 0. sativa L.
hirger islands. Rosclievicz (53) ^ reported a com- var. fatua Prain; O. stapf i Roschev. ; and 0.
prehensive study of the genus, and he concluded sxihvJata Nees. Four species were recognized by
from his study that there were 20 species of Tateoka (6'4) but not by Chatterjee {13) so they
Orysa.^ Chevalier {lo) reported a similar study were not listed in table 2. These are 0. angu^stJ'
in which he recognized 22 species. Chatterjee folia Hubbard; 0. IjarthU A. Cheval.; 0. longi-
i IS) later summarized the information on Ort/2a gluwis Jansen; and 0. rufpogen Griff. The
and listed 28 species. Tateoka (64) summarized cliromosome number of the species of Oryza as
the information on species of Oryza in 1968 and reported by Kihara (35) and the distribution as
recognized 22 valid species. The 18 species that reported bv Chatterjee {14) also are shown in
were recognized by both Chatterjee {13) and table 2.
TABLE 2.—Species, chromosome rmmher. and elistriljiition of O rvza
Chromo
Species some Xc Distribution
f2n)
1. 0. alta Swallen 24 and 4S South America and Central America.
2. 0. australiensis Domiii __ 24 Australia.
3. 0. brachyantha A. Cheval. ¿k Roelir. 24 West Tropical Africa and Central Africa.
4. 0. bre vil if/ida ta A. Cheval. (fc Roehr. 24 West Tr(»pical Africa.
5. 0. coarctata Roxb. 48 India and Burma.
*3. 0. eichinrjeri Peter 48 East Africa.
T. 0. [jlabrrrlma Steiid. 24 W>st Tropical Africa and Central America.^
S, 0. rjrandirjlumis fDoeU ) Prorloehl 24 and 48 South America.
9. 0. JatifoJia Desv. 48 Central America, South America, and West Indies.
10. 0. meyeriana (Zoll. *fc Mor.) I>aill. 24 .Java, Borneo, Philippines, and Siam.
11. 0. minuta Presl 48 Malay Peninsula, Philippines, Sumatra, Java, and
Borneo.
12. 0. offlcinalis Wall, ex Watt __ 24 India and Burma,
13. 0. perrieri A. Camus ^ladagascar.
14. 0. punctata Kotschy ex Steiid. Northeast Tropical Africa.
15. 0. ridleyi Hook. f. I 48 ^lahiy PetiÍnsula, Siam, Borneo, and New Guinea.
16. 0. sativa L. 24 and 48 India and Indo-China.
IT. 0. srlilechteri Pilger New Guinea.
IS. 0. tisseranti A. Cheval. Cnntral Africa.
1 P.I. 269630. Collected in El Salvador by H. M. Beaohell and identitied l)y Eugf-iip Critlith, Crops Research
1 Mvision, Agricultural Research Service, Beltsville, Md., and J. R. Swallen, Smithsonian Institution, Washington, D.C.
Rosclievicz (53) divided the species of Oryza tion and nomenclature of Oryza and recommended
into four sections on the basis of morpholo<ric that standards be adopted and used uniformly.
characters and geographic distribution. Kihara This committee recognized 19 valid species of
(35) modified this grouping to include species not Oryza. Seventeen of these species are listed in
reported by Roschevicz. table 2. The species not recognized by this com-
In 1963, a committee ^ reviewed the classifica- mittee tliat is listed in table 2 is O, graiidiefivmix.
The other two species recognized l3y this com-
1 Italic numbers in parentheses refer to Selected Refer-
mittee ai'e 0. angastifalia and O. longiglnrnis.
ences, p. 16.
2 This committee was appointed at the Rice Genetii^* The committee also believed that certain aspects
Symposium convened at the International Rice Research of taxonomy in Oryza are uncertain. These are:
Institute, Los Banos, the Philippines. The members w^ere
(1) The relation and nomenclature among i\\^
S. Sampath, India ; T. Tateoka, .lapan ; and M. T. Hen-
derson, United States. taxa commonly designated as Ö. saliva var. fatvba
AGMí ! i rUiœ HANDBOOK 2 8 9, U.S. DEPT. OF AGRICULTURE
(or /. spontanea RosclieA,:' uid 0. perenm's were duplicated, probably due to meiotic irregu-
(Asiatic, American, and Afriraii) subspecies and hirities in the hybrid. This followed by a subse-
varieties; (2) the relation of the form commonly ((uent doubling of the chromosomes attained the
designated 0. stapfii to 0, glahemmu and 0. bre- secondary balance of n = 12, the present existing
viUgulata; (3) the relation between 0. gramdata number of 0. sativa'''^ (4-^).
f. and 0. imyerkma; (4) the relation between 0. Sampath and Rao {56) "inferred that Oryza
alta and 0. grandiglumis; and (5) the status of perennis is the ancestral form of cultivated rices,
the taxa previously designated 0. ubœnghemi>< having given rise to 0. sativa in Asia and 0. gla-
Chev. and 0, malampuzhaensls Krish. and Chand. herrima in Africa by human selection." These
The committee also believed that the form com- authors were of the opinion that 0, hreviligulata
monly designated 0. subid at a should be excluded and 0. sativa var. fatua are of collateral descent
irom Oryza and should be recognized as Rhyn- from O. perennis. The present types that are
choryza subuhta (Nees) Baill. classified as O. sativa var. fatua or spoiitanea
Chatter]ee (li) reviewed the literature on the show morphologic differences that may be due to
origin and distribution of wild and cultivated genetic transfer from cultivated rice. From this
rice. He concluded that the eastern part of it is inferred that these wild forms are derived
India, Indo-China, and part of China could be from hybrids with cultivated rices and are not
considered the area where cultivated rice {Oryza the progenitors of cultivated rice. Instead it has
sativa) originated. Chatterjee further concluded, been strongly suggested {55, 56. 70) that an inter-
as did Roschevicz (55), that for the genus as a mediate type may be the immediate ancestor of
whole or the section Sativa Roschev., the center O. sativa-.
of origin is Africa. He was of the opinion that
0, altas 0. aii^tralieiisis^ 0, hixichyantha, 0, Description and Development of the
eichingeri^ 0, grandiglumis^ 0. latí folia, 0. mm-
Rice Plant and Classification
uta^ 0, pemeri, 0. schlechteH^ 0. subidata^ and
of Cultivated Varieties
0. tisseranti had little part in the ancestry of cul-
tivated rice. This view seems to be based either
Cultivated varieties of (9. sativa are divided
on the fact that these species do not cross with
into groups on the basis of several characters.
0, sativa or on the fact that they occur naturally
The principal division is on the basis of sterility
in areas far removed from the center where rice
of the hybrid. Kato and others {33, 31^) observed
cultivation orimnated.
that in crosses of certain varieties from the tem-
Many investigators have studied and discussed
perate zone and certain varieties from tropical
the origin of the genus Oryza and of cultivated
areas, the hybrids had a high percentage of sterile
rice {13, U, 15, 35, 1^6, 1^8. 50, 53, 55, 56, 67, 70),
florets. The hybrids between varieties within
It is generally concluded that the original ances-
these two groups were as fertile as self-pollinated
tral species may no longer exist and that present
parent varieties.
varieties evolved through progressive stages from
They proposed that the temperate zone varieties
known wild species {56).
be named japónica and the tropical zone varieties
Nandi {U) and Sakai (5^) proposed that a
indica. Kato and others {31^) observed no differ-
species with a haploid number of five chromo-
ence between japónica and indica varieties in
somes was the ancestor of Oryza. This proposal
chromosome number and behavior or in pollen
was rather widely accepted. Nandi (^4) observed
formation. However, in the hybrid, pollen for-
that in the somatic complement having 24 chro-
mation Avas abnormal. Serological investigations
mosomes there were two members of eight types
showed differences between japónica and indica
and four members of two types. The maximum
varieties.
association in second metaphase was two groups
Later, Terao and Midusima {66) noted that
of three and three groups of two. It was con-
another group of varieties, principally from trop-
cluded from this observation that the haploid
genome of the present 0. satina is composed of ical islands of Southeast Asia, were intermediate.
two original five-paired species belonging to two This last group is referred to as bulu.
different ancestral genomes in which two chro- It appeared from the earlier studies that the
mosomes were duplicated. varieties could be divided into three distinct
Later, Shastry, Rao, and Misra {60) identified groups based on sexual affinity. Mizushima {39),
12 pachytine bivalents in a strain of 0. sativa. however, determined that this was not true and
based on their length and arm ratios. This find- that sexual affinities among varieties from these
ing seems to cast considerable doubt on the val- groups varied gradually from one extreme to the
idity of the supposition "that O. sativa is a sec- other.
ondarily balanced allo-tetraploid which origin- Oka (^5) compared 147 varieties from widely
ated through hybridization between two different
different geographic areas on the basis of a num-
five-paired species in which two chromosomes
ber of morphologic and physiologic characters