0 [
`
`11] Patent Number:
`
`[45] Date of Patent:
`
`5,545,813
`Aug. 13, 1996
`
`United States Patent 15
`Piper
`
`[54]
`
`INBRED MAIZE LINE PHRF5
`
`(75]
`
`Inventor: Todd E. Piper, Eau Claire County, Wis.
`
`[73] Assignee: Pioneer Hi-Bred International, Inc.,
`Des Moines, lowa
`
`[21] Appl. No.: 381,454
`
`[22]
`
`Filed:
`
`Jan. 31, 1995
`
`[S51]
`
`Ean. CLS cccccccccscccesseeseeeee AO1H 5/00; AOIH 4/00;
`AO1H 1/00; C12H 5/04
`[52] US. Ch cesses 800/200; 800/250; 800/DIG. 56;
`435/240.4; 435/240.49; 435/240.5; 47/58
`[58] Field of Search ...sscccsssseseersesceeeseeee 800/200, 205,
`800/250, DIG. 56; 47/58.03, 58.05; 435/172.3,
`240.4, 145.5
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`4,812,599
`5,082,992
`
`3/1989 Segebart .
`1/1992 Ambrose etal. ..sscseeseeeen 800/200
`
`FOREIGN PATENT DOCUMENTS
`
`160390
`
`.
`European Pat. Off.
`6/1985
`OTHER PUBLICATIONS
`
`Conger, B. V., et al. (1987) “Somatic Embryogenesis From
`Cultured Leaf Segments of Zea Mays”, Plant Cell Reports,
`6:345-347.
`Duncan, D. R., et al. (1985) “The Production of Callus
`Capable of Plant Regeneration From Immature Embryos of
`Numerous Zea Mays Genotypes”, Plania, 165:322-332.
`Edallo, et al.
`(1981) “Chromosomal Variation and Fre-
`quency of Spontaneous Mutation Associated with in Vitro
`Culture and Plant Regeneration in Maize’, Maydica, XXVI:
`3956.
`(1975) “Plant Regeneration From Tissue
`Green, et al.,
`Cultures of Maize”, Crop Science, vol. 15, pp. 417-421.
`Green, C. E., et al. (1982) “Plant Regeneration in Tissue
`Cultures of Maize” Maize for Biological Research, pp.
`367-372.
`Hallauer, A. R. et al. (1988) “Corn Breeding” Corn and
`Corn Improvement, No. 18, pp. 463-481.
`Meghiji, M.R.et al. (1984). “Inbreeding Depression, Inbred
`& Hybrid Grain Yields, and Other Traits of Maize Geno-
`types Representing Three Eras”, Crop Science, vol. 24, pp.
`545-549.
`
`(1988) “Cell/Tissue Culture and In Vitro
`Philips, et al.
`Manipulation”, Corn & Corn Improvement, 3rd Ed., ASA
`Publication, No. 18, pp. 345-387.
`Poehlman (1987) Breeding Field Crop, AVI Publication Co.,
`Westport, Ct., pp. 237-246.
`Rao,K.V., et al., (1986)“Somatic Embryogenesis in Glume
`Callus Cultures”, Maize Genetics Cooperative Newsletier,
`No. 60, pp. 64-65.
`Sass, John F. (1977) “Morphology”, Corn & Corn Improve-
`ment, ASA Publication, Madison, Wisconsin, pp. 89-109.
`Songstad, D. D.
`et
`al.
`(1988)
`“Effect of ACC
`(1-aminocyclopropane—1—carboxyclic acid), Silver Nitrate
`& Norbonadiene on Plant Regeneration From Maize Callus
`Cultures”, Plant Cell Reports, 7:262-265.
`Tomes, et al. (1985) “The Effect of Parental Genotype on
`Initiation of Embryogenic Callus From Elite Maize (Zea
`Mays L.) Germplasm”, Theor. Appl. Genet., vol. 70, pp.
`505-509.
`
`Troyer, et al. (1985) “Selection for Early Flowering in Corn:
`10 Late Synthetics”, Crop Science, vol. 25, pp. 695-697.
`Umbeck,et al. (1983) “Reversion of Male~Sterile T-Cyto-
`plasm Maize to Male Fertility in Tissue Culture”, Crop
`Science, vol. 23, pp. 584-588.
`Wright, Harold (1980) “Commerical Hybrid Seed Produc-
`tion”, Hybridization of Crop Plants, Ch. 8: 161-176.
`Wych, Robert D. (1988) ‘Production of Hybrid Seed”, Corn
`and Corn Improvement, Ch. 9, pp. 565-607.
`Lee, Michael (1994) “Inbred Lines of Maize and Their
`Molecular Markers”, The Maize Handbook Ch. 65:423-432.
`Boppenmaier, et al., “Comparsons AmongStrains of Inbreds
`for RFLPs”, Maize Genetics Cooperative Newsletter,
`65:1991, p. 90.
`
`Primary Examiner—Gary Benzion
`Attorney, Agent, or Firm—Pioneer Hi-Bred International,
`Inc.
`
`[57]
`
`ABSTRACT
`
`An inbred maize line, designated PHRF5, the plants and
`seeds of inbred maize line PHRF5, methods for producing a
`maize plant produced by crossing the inbred line PHRF5
`with itself or with another maize plant, and hybrid maize
`seeds and plants produced by crossing the inbred line
`PHRF5 with another maize line or plant.
`
`13 Claims, No Drawings
`
`Inari Exhibit 1047
`Inari Exhibit 1047
`Inari v. Pioneer
`Inari v. Pioneer
`
`

`

`1
`INBRED MAIZE LINE PHRFS
`
`FIELD OF THE INVENTION
`
`This invention is in the field of maize breeding, specifi-
`cally relating to an inbred maize line designated PHRF5.
`
`BACKGROUND OF THE INVENTION
`
`The goal of plant breeding is to combine in a single
`variety or hybrid various desirable traits. For field crops,
`these traits may include resistance to diseases and insects,
`tolerance to heat and drought, reducing the time to crop
`maturity, greater yield, and better agronomic quality. With
`mechanical harvesting of many crops, uniformity of plant
`characteristics such as germination and stand establishment,
`growthrate, maturity, and plant and ear height, is important.
`Field crops are bred through techniques that take advan-
`tage of the plant’s method of pollination. A plant is self-
`pollinated if pollen from one flower is transferred to the
`same or another flower of the same plant. A plant
`is
`cross-pollinated if the pollen comes from a flower on a
`different plant.
`Plants that have beenself-pollinated and selected for type
`for many generations become homozygous at almost all
`gene loci and produce a uniform population oftrue breeding
`progeny. A cross between two different homozygouslines
`produces a uniform population of hybrid plants that may be
`heterozygous for many geneloci. A cross of two plants each
`heterozygous at a number of gene loci will produce a
`population of hybrid plants that differ genetically and will
`not be uniform.
`
`Maize (zea mays L.), often referred to as corn in the
`United States, can be bred by both self-pollination and
`cross-pollination techniques. Maize has separate male and
`female flowers on the sameplant, located on the tassel and
`the ear, respectively. Natural pollination occurs in maize
`when wind blows pollen from the tassels to the silks that
`protrude from the tops ofthe ears.
`A reliable method of controlling male fertility in plants
`offers the opportunity for improved plant breeding. This is
`especially true for development of maize hybrids, which
`relies upon some sort of male sterility system. There are
`several options for controlling male fertility available to
`breeders, such as: manual or mcchanical emasculation(or
`detasseling), cytoplasmic male sterility, genetic male steril-
`ity, gametocides and the like.
`Hybrid maize seed is typically produced by a male
`sterility system incorporating manual or mechanical detas-
`seling. Alternate strips of two inbred varieties of maize are
`planted in a field, and the pollen-bearing tassels are removed
`from one of the inbreds (female). Providing that there is
`sufficientisolation from sources of foreign maize pollen, the
`ears of the detasseled inbred will be fertilized only from the
`other inbred (male), and the resulting seed is therefore
`hybrid and will form hybrid plants.
`The laborious, and occasionally unreliable, detasseling
`process can be avoided by using cytoplasmic male-sterile
`(CMS)inbreds. Plants of a CMSinbred are malesterile as
`aresult of factors resulting from the cytoplasmic, as opposed
`to the nuclear, genome. Thus,this characteristic is inherited
`exclusively through the female parent in maize plants, since
`only the female provides cytoplasm to the fertilized seed.
`CMSplants are fertilized with pollen from another inbred
`that is not male-sterile. Pollen from the second inbred may
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`or may not contribute genes that make the hybrid plants
`male-fertile. Usually seed from detasseled fertile maize and
`CMSproducedseed of the same hybrid are blended to insure
`that adequate pollen loads are available for fertilization
`when the hybrid plants are grown.
`There are several methods of conferring genetic male
`sterility available, such as multiple mutant genes at separate
`locations within the genome that confer malesterility, as
`disclosed in U.S. Pat. Nos. 4,654,465 and 4,727,219 to Brar
`et al. and chromosomal
`translocations as described by
`Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. These
`and all patents referred to are incorporated by reference. In
`addition to these methods, Albertsen et al., of Pioneer
`Hi-Bred, U.S. patent application Ser. No. 07/848,433, have
`developed a system of nuclear male sterility which includes:
`identifying a gene whichis critical to male fertility; silenc-
`ing this native gene which is critical
`to male fertility;
`removing the native promoter from the essential male fer-
`tility gene and replacing it with an inducible promoter;
`inserting this genetically engineered gene back into the
`plant; and thus creating a plant that is male sterile because
`the inducible promoter is not “on” resulting in the male
`fertility gene not being transcribed. Fertility is restored by
`inducing,or turning “on”, the promoter, which in turn allows
`the gene that confers male fertility to be transcribed.
`There are many other methods of conferring genetic male
`sterility in the art, each with its own benefits and drawbacks.
`These methods use a variety of approaches such as deliv-
`ering into the plant a gene encoding a cytotoxic substance
`associated with a male tissue specific promoter or an anti-
`sense system in which a genecritical to fertility is identified
`and an antisense to that gene is inserted in the plant (see:
`Fabinjanski, et al. EPO 89/3010153.8 publication no. 329,
`308 and PCT application PCT/CA90/00037 published as
`WO 90/08828).
`Another system useful in controlling male sterility makes
`use of gametocides. Gametocides are not a genetic system,
`but rather a topical application of chemicals. These chemi-
`cals affect celis that are critical to male fertility. The appli-
`cation of these chemicals affects fertility in the plants only
`for the growing season in which the gametocide is applied
`(see Carlson, Glenn R., U.S. Pat. No. 4,936,904). Applica-
`tion of the gametocide, timing of the application and geno-
`type specificity often limit the usefulness of the approach.
`The use of male sterile inbreds is but one factor in the
`production of maize hybrids. The development of maize
`hybrids requires, in general, the development of homozy-
`gous inbred lines,
`the crossing of these lines, and the
`evaluation of the crosses. Pedigree breeding and recurrent
`selection breeding methods are used to develop inbredlines
`from breeding populations. Breeding programs combinethe
`genetic backgrounds from two or more inbred lines or
`various other broad-based sources into breeding pools from
`which new inbred lines are developed by selfing and selec-
`tion of desired phenotypes. The new inbreds are crossed
`with other inbred lines and the hybrids from these crosses
`are evaluated to determine which of those have commercial
`potential.
`Pedigree breeding starts with the crossing of two geno-
`types, each of which may have one or more desirable
`characteristics that is lacking in the other or which comple-
`ments the other. If the two original parents do not provide all
`the desired characteristics, other sources can be included in
`the breeding population. In the pedigree method, superior
`plants are selfed and selected in successive generations. In
`the succeeding generations the heterozygous condition gives
`
`

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`5,545,813
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`3
`way to homogeneouslinesas a result of self-pollination and
`selection. Typically in the pedigree method of breeding five
`or more generations of selfing and selection is practiced:
`F,F,; F3;3F,; F,F,,ete.
`Recurrent selection breeding, backcrossing for example,
`can be used to improve an inbred line. Backcrossing can be
`used to transfer a specific desirable trait from one inbred or
`source to an inbred that lacks thattrait. This can be accom-
`plished, for example, by first crossing a superior inbred
`(recurrent parent) to a donor inbred (non-recurrent parent),
`that carries the appropriate gene(s) for the trait in question.
`The progenyof this cross is then mated back to the superior
`recurrent parent followed by selection in the resultant prog-
`eny for the desired trait to be transferred from the non-
`recurrent parent. After five or more backcross generations
`with selection for the desired trait,
`the progeny will be
`heterozygous for loci controlling the characteristic being
`transferred, but will be like the superior parent for most or
`almostall other genes. The last backcross generation is then
`selfed to give pure breeding progeny for the gene(s) being
`transferred.
`
`A single cross hybrid maize variety is the cross of two
`inbred lines, each of which has a genotype that complements
`the genotype of the other. The hybrid progeny ofthe first
`generation is designated F,. In the development of hybrids
`only the F, hybrid plants are sought. Preferred F, hybrids are
`more vigorous than their inbred parents. This hybrid vigor,
`or heterosis, can be manifested in many polygenic traits,
`including increased vegetative growth and increased yield.
`The developmentof a hybrid maize variety involves three
`steps: (1) the selection of plants from various germplasm
`pools for initial breeding crosses;
`(2) the selfing of the
`selected plants from the breeding crosses for several gen-
`erations to produce a series of inbred lines, which, although
`different from each other, breed true and are highly uniform;
`and (3) crossing the selected inbred lines with different
`inbred lines to produce the hybrid progeny (F,). During the
`inbreeding process in maize,the vigor of the lines decreases.
`Vigor is restored when twodifferent inbred lines are crossed
`to produce the hybrid progeny (F,). An important conse-
`quence of the homozygosity and homogeneity is of the
`inbredlines is thal the hybrid between any two inbredswill
`always be the same. Oncethe inbreds that give a superior
`hybrid have been identified, the hybrid seed can be repro-
`duced indefinitely as long as the homogeneity of the inbred
`parents is maintained.
`‘A single cross hybrid is produced when two inbredlines
`are crossed to produce the F, progeny. A double cross hybrid
`is produced from four inbred lines crossed in pairs (AXB and
`CxD)and then the two F, hybrids are crossed again (AxB)x
`(CxD). Much of the hybrid vigor exhibited by F, hybrids is
`lost in the next generation (F,). Consequently, seed from
`hybrid varieties is not used for planting stock.
`Maize is an important and valuable field crop. Thus, a
`continuing goal of plant breeders is to develop high-yielding
`maize hybrids that are agronomically sound based onstable
`inbred lines. The reasons for this goal are obvious:
`to
`maximize the amountof grain produced with the inputs used
`and minimize susceptibility of the crop to environmental
`stresses. To accomplish this goal, the maize breeder must
`select and develop superior inbred parental lines for pro-
`ducing hybrids. This requires identification and selection of
`genetically unique individuals that occur in a segregating
`population. The segregating population is the result of a
`combination of crossover events plus the independent
`assortmentof specific combinations of alleles at many gene
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`loci that results in specific genotypes. Based on the number
`of segregating genes, the frequency of occurrence of an
`individual with a specific genotype is less than 1 in 10,000.
`Thus, even if the entire genotype of the parents has been
`characterized andthe desired genotype is known,only a few
`if any individuals having the desired genotype may be found
`in a large F, or Sy population. Typically, however,
`the
`genotype ofneither the parents nor the desired genotype is
`known in any detail.
`In addition to the preceding problem,it is not known how
`the genotype will react with the environment. This genotype
`by environment interaction is an important, yet unpredict-
`able, factor in plant breeding. A breeder of ordinary skill in
`the art cannot predict the genotype, how that genotype will
`interact with various environments or the resulting pheno-
`types of the developing lines, except perhaps in a very broad
`and general fashion. A breeder of ordinary skill] in the art
`would also be unableto recreate the sameline twice from the
`very sameoriginal parents as the breeder is unableto direct
`how the genomes combineor how they will interact with the
`environmental conditions. This unpredictability results in
`the expenditure of large amounts of research resourcesin the
`development of a superior new maize inbredline.
`Pioneer research station staff propose about 400 to 500
`new inbreds each year from over 2,000,000 pollinations. Of
`those proposed new inbreds, less than 50 and more com-
`monly less than 30 are actually selected for commercial use.
`
`SUMMARY OF THE INVENTION
`
`According to the invention, there is provided a novel
`inbred maize line, designated PHRFS. This invention thus
`relates to the seeds of inbred maize line PHRF5, to the plants
`of inbred maize line PHRFS, and to methods for producing
`a maize plant produced by crossing inbred maize line
`PHRF5 with itself or another maize line. This invention
`furtherrelates to hybrid maize seeds and plants produced by
`crossing the inbred line PHRF5 with another maizeline.
`
`Definitions
`
`In the description and examplesthat follow, a number of
`terms are used herein. In order to provide a clear and
`consistent understanding of the specification and claims,
`including the scope to be given such terms, the following
`definitions are provided. NOTE: ABS is in absolute terms
`and % MNis percent of the mean for the experiments in
`which the inbred or hybrid was grown. These designators
`will follow the descriptors to denote how the values are to
`be interpreted. Below are the descriptors uscd in the data
`tables included herein.
`
`ANT ROT=ANTHRACNOSESTALK ROT(Colletotri-
`chum graminicola). A 1 to 9 visual rating indicating the
`resistance to AnthracnoseStalk Rot. A higherscore indicates
`a higher resistance.
`BAR PLT=BARRENPLANTS. Thepercentof plants per
`plot that were not barren (lack ears).
`BRT STK=BRITTLE STALKS. This is a measure of the
`stalk breakage near the time of pollination, and is an
`indication of whether a hybrid or inbred would snap or break
`near the time of flowering under severe winds. Data are
`presented as percentage of plants that did not snap.
`BU ACR=YIELD (BUSHELS/ACRE). Yield of the grain
`at harvest in bushels per acre adjusted to 15.5% moisture.
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`5,545,813
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`6
`temperatures
`temperature range 50° F-86° F and that
`outside this range slow down growth; the maximum daily
`heat unit accumulation is 36 and the minimum daily heat
`unit accumulation is 0. The seasonal accumulation of GDU
`is a major factor in determining maturity zones.
`GDU SHD=GDU TO SHED. The number of growing
`degree units (GDUs) or heat units required for an inbred line
`or hybrid to have approximately 50 percent of the plants
`shedding pollen and is measured from the time ofplanting.
`Growing degree units are calculated by the Barger Method,
`where the heat units for a 24-hour period are:
`
`5
`CLN=CORN LETHAL NECROSIS. Synergistic interac-
`tion of maize chlorotic mottle virus (ACMV)in combina-
`tion with either maize dwarf mosaic virus (MDMV-A or
`MDMV-B)or wheat streak mosaic virus (WSMV). A | to 9
`visual rating indicating the resistance to Corn Lethal Necro-
`sis. A higher score indicates a higher resistance.
`COM RST=COMMONRUST(Puccinia sorghi). A 1 to
`9 visual rating indicating the resistance to Common Rust. A
`higher score indicates a higher resistance.
`D/D=DRYDOWN. This represents the relative rate at
`which a hybrid will
`reach acceptable harvest moisture
`comparedto other hybrids on a 1-9 rating scale. A high score
`
`Gpy=Maxtemp.+Mintemp.)__ 5
`indicates a hybrid that dries relatively fast while a low score
`indicates a hybrid that dries slowly.
`me 5
`DIP ERS=DIPLODIA EAR MOLD SCORES (Diplodia
`maydis and Diplodia macrospora). A 1
`to 9 visual rating
`indicating the resistance to Diplodia Ear Mold. A higher
`score indicates a higher resistance.
`DRP EAR=DROPPED EARS. A measure of the number
`of dropped ears per plot and represents the percentage of
`planis that did not drop ears prior to harvest.
`D/T=DROUGHT TOLERANCE.This represents a 1-9
`rating for drought tolerance, and is based on data obtained
`under stress conditions. A high score indicates good drought
`tolerance and a low score indicates poor drought tolerance.
`EAR HT=EAR HEIGHT. The ear height is a measure
`from the ground to the highest placed developed ear node
`attachment and is measured in inches.
`
`The highest maximum temperature used is 86° F. and the
`lowest minimum temperature used is 50° F. For each inbred
`or hybrid it takes a certain number of GDUsto reach various
`stages of plant development.
`GDU SLK=GDU TO SILK. The number of growing
`degree units required for an inbred line or hybrid to have
`approximately 50 percentof the plants with silk emergence
`from time of planting. Growing degree units are calculated
`by the Barger Method as given in GDU SHDdefinition.
`GIB ERS=GIBBERELLA EAR ROT (PINK MOLD)
`(Gibberella zeae). A 1
`to 9 visual rating indicating the
`resistance to Gibberella Ear Rot. A higher score indicates a
`higherresistance.
`EAR MLD=General Ear Mold. Visual rating (1-9 score)
`GLF SPT=Gray Leaf Spot (Cercospora zeae-maydis). A 1
`where a “1” is very susceptible and a “9”is very resistant.
`to 9 visual rating indicating the resistance to Gray Leaf Spot.
`This is based on overall rating for ear mold of mature ears
`A higher score indicates a higher resistance.
`without determining the specific mold organism, and may
`GOS WLT=Goss’ Wilt (Corynebacterium nebraskense).
`not be predictive for a specific ear mold.
`A1to 9 visual rating indicating the resistance to Goss’ Wilt.
`EAR SZ=EAR SIZE.A 1 to 9 visual rating of ear size. The
`A higher score indicates a higher resistance.
`35
`to 9
`GRN APP=GRAIN APPEARANCE. This is a 1
`higher the rating the larger the ear size.
`ECB 1LF=EUROPEAN CORN BORER FIRST GEN-
`rating for the general appearanceof the shelled grain asit is
`harvested based on such factors as the color of harvested
`ERATION LEAF FEEDING (Ostrinia nubilalis). A 1 to 9
`grain, any mold on the grain, and any cracked grain. High
`visual rating indicating the resistance to preflowering leaf
`feeding by first generation European Corn Borer. A higher
`scores indicate good grain quality.
`score indicates a higher resistance.
`H/POP=YIELD AT HIGH DENSITY. Yield ability at
`ECB 2IT=EUROPEAN CORN BORER SECOND GEN-
`relatively high plant densities on 1-9 relative rating system
`ERATION INCHES OF TUNNELING(Ostrinia nubilalis).
`with a higher numberindicating the hybrid responds well to
`Average inches of tunneling per plant in the stalk.
`high plant densities for yield relative to other hybrids. A 1,
`ECB 2SC=EUROPEAN CORN BORER SECOND
`5, and 9 would represent very poor, average, and very good
`yield response, respectively, to increased plant density.
`GENERATION(Ostrinia nubilalis). A 1 to 9 visual rating
`HC BLT=HELMINTHOSPORIUM CARBONUM LEAF
`indicating post flowering degree of stalk breakage and other
`BLIGHT (Helminthosporium carbonum). A 1
`to 9 visual
`evidence of feeding by European Corn Borer, Second Gen-
`eration. A higher score indicates a higher resistance.
`rating indicating the resistance to Helminthosporium infec-
`ECB DPE=EUROPEAN CORN BORER DROPPED
`tion. A higher score indicates a higher resistance.
`EARS(Ostrinia nubilalis). Dropped ears due to European
`HD SMT=HEAD SMUT (Sphacelotheca reiliana). This
`Corn Borer. Percentage ofplants that did not drop ears under
`score indicates the percentage of plants not infected.
`second generation corn borer infestation.
`INC D/A=GROSS INCOME (DOLLARS PER ACRE).
`EST CNT=EARLY STAND COUNT.This is a measure
`Relative incomeper acre assuming drying costs of two cents
`of the stand establishment in the spring and represents the
`per point above 15.5 percent harvest moisture and current
`numberofplants that emerge on perplot basis for the inbred
`market price per bushel.
`or hybrid.
`INCOME/ACRE.Incomeadvantage of hybrid to be pat-
`EYE SPT=Eye Spot (Kabatiella zeae or Aureobasidium
`ented over other hybrid on per acre basis.
`INC ADV=GROSS INCOME ADVANTAGE. GROSS
`zeae). A 1 to 9 visual rating indicating the resistance to Eye
`Spot. A higher score indicates a higher resistance.
`INCOMEadvantage of variety #1 over variety #2.
`FUS ERS=FUSARIUM EAR-ROT SCORE (Fusarium
`L/POP=YIELD AT LOW DENSITY. Yield ability at
`moniliforme or Fusarium subglutinans). A 1
`to 9 visual
`relatively low plant densities on a 1-9 relative system with
`rating indicating the resistance to Fusarium ear rot. A higher
`a higher numberindicating the hybrid responds well to low
`score indicates a higher resistance.
`plant densities for yield relative to other hybrids. A 1, 5, and
`GDU=Growing Degrec Units. Using the Barger Heat Unit
`9 would represent very poor, average, and very good yield
`Theory, which assumes that maize growth occurs in the
`response, respectively, to low plant density.
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`MDM CPX=MAIZE DWARF MOSAIC COMPLEX
`(MDMV=Maize Dwarf Mosaic Virus and MCDV=Maize
`Chlorotic Dwarf Virus). A 1 to 9 visual rating indicating the
`resistance to Maize Dwarf Mosaic Complex. A higher score
`indicates a higher resistance.
`MST=HARVEST MOISTURE.The moisture is the actual
`percentage moisture of the grain at harvest.
`MST ADV=MOISTURE ADVANTAGE. The moisture
`advantage of variety #1 over variety #2 as calculated by:
`MOISTURE of
`variety
`#2-MOISTURE of
`variety
`#1=MOISTURE ADVANTAGEofvariety #1.
`NLF BLT=Northern Leaf Blight
`(Helminthosporium
`turcicum or Exserohilum turcicum). A 1 to 9 visual rating
`indicating the resistance to Northern Leaf Blight. A higher
`score indicates a higherresistance.
`PLT HT=PLANT HEIGHT. This is a measure of the
`height ofthe plant from the groundto the tip of the tassel in
`inches.
`
`15
`
`POL SC=POLLEN SCORE.A 1 to 9 visual rating indi-
`cating the amount of pollen shed. The higher the score the
`more pollen shed.
`POL WT=POLLEN WEIGHT.This is calculated by dry
`weight of tassels collected as shedding commences minus
`dry weight from similar tassels harvested after shedding is
`complete.
`through
`the inbred can,
`It should be understood that
`routine manipulation of cytoplasmic or other factors, be
`producedin a male-sterile form. Such embodimentsare also
`contemplated within the scope of the present claims.
`POP K/A=PLANT POPULATIONS. Measured as 1000s
`per acre.
`POP ADV=PLANT POPULATION ADVANTAGE.The
`plant population advantage of variety #1 over variety #2 as
`calculated by PLANT POPULATION of variety #2 0
`PLANT POPULATIONofvariety #1=PLANT POPULA-
`TION ADVANTAGEofvariety #1.
`PRM=PREDICTED RELATIVE MATURITY. Thistrait,
`predicted relative maturity, is based on the harvest moisture
`ofthe grain. Therelative maturity rating is based on a known
`set of checks and utilizes standard linear regression analyses
`andis also referred to as the Comparative Relative Maturity
`Rating System that is similar to the Minnesota Relative
`Maturity Rating System.
`PRM SHD=Arelative measure of the growing degree
`units (GDU) required to reach 50% pollen shed. Relative
`values are predicted values from the linear regression of
`observed GDU’s onrelative maturity of commercial checks.
`RT LDG=ROOT LODGING.Rootlodgingis the percent-
`age ofplants that do notrootlodge; plants that lean from the
`vertical axis at an approximately 30° angle or greater would
`be counted as root lodged.
`RTL ADV=ROOT LODGING ADVANTAGE.The root
`lodging advantage of variety #1 over variety #2.
`SCT GRN=SCATTER GRAIN. A I
`to 9 visual rating
`indicating the amountofscatter grain (lackof pollination or
`kernel abortion) on the car. The higher the score the less
`scatter grain.
`SDG VGR=SEEDLING VIGOR.This is the visual rating
`YLD ADV=YIELD ADVANTAGE.Theyield advantage
`(1 to 9) of the amount of vegetative growth after emergence
`of variety #1 over variety #2 as calculated by: YIELD of
`at the seedling stage (approximately five leaves). A higher
`variety #1=YIELDvariety #2=yield advantageof variety #1.
`score indicates better vigor.
`SEL IND=SELECTION INDEX. The selection index
`YLD SC=YIELD SCORE. A1to 9 visual rating was used
`to give a relative rating for yield based on plot ear piles. The
`gives a single measure of the hybrid’s worth based on
`higher the rating the greater visual yield appearance.
`informationfor upto five traits. A maize breeder may utilize
`
`8
`his or her ownsetoftraits for the selection index. Oneof the
`traits that is almost always included is yield. The selection
`index data presented in the tables represent the mean value
`averaged across testing stations.
`SLF BLT=SOUTHERN LEAF BLIGHT (Helminthospo-
`rium maydis or Bipolaris maydis). A 1 to 9 visual rating
`indicating the resistance to Southern Leaf Blight. A higher
`score indicates a higher resistance.
`SOU RST=SOUTHERN RUST(Puccinia polysora). A1
`to 9 visual rating indicating the resistance to Southern Rust.
`A higher score indicates a higher resistance.
`STA GRN=STAY GREEN. Stay green is the measure of
`plant health near the time of black layer formation (physi-
`ological maturity). A high score indicates better late-season
`plant health.
`STD ADV=STALK STANDING ADVANTAGE. The
`advantage of variety #1 over variety #2 for the trait STK
`CNT.
`STK CNT=NUMBER OF PLANTS. This is the final
`stand or numberofplants per plot.
`STK LDG=STALK LODGING.Thisis the percentage of
`plants that did not stalk lodge (stalk breakage) as measured
`by either natural lodging or pushing the stalks and deter-
`mining the percentage of plants that break below the ear.
`STW WLT=Stewart’s Wilt (Erwinia stewartit). A 1
`to 9
`visual rating indicating the resistance to Stewart’s Wilt. A
`higher score indicates a higher resistance.
`TAS BLS=TASSEL BLAST. A 1 to 9 visual rating was
`used to measure the degree of blasting (necrosis due to heat
`stress) of the tassel at the time of flowering. A 1 would
`indicate a very high level of blasting at time of flowering,
`while a 9 would have notassel blasting.
`TAS SZ=TASSELSIZE. A 1 to 9 visual rating was used
`to indicate the relative size of the tassel. The higher the
`rating the larger the tassel.
`TAS VVT=TASSEL WEIGHT.Thisis the average weight
`of a tassel (grams) just prior to pollen shed.
`TEX EAR=EAR TEXTURE.A I to 9 visual rating was
`used to indicate the relative hardness (smoothness of crown)
`of mature grain. A 1 would be very soft (extreme dent) while
`a 9 would be very hard (flinty or very smooth crown).
`TILLER=TILLERS. A count of the numberoftillers per
`plot that could possibly shed pollen was taken. Data is given
`as a percentage oftillers: numberoftillers per plot divided
`by numberof plants per plot.
`TST WT=TEST WEIGHT (UNADJUSTED). The mea-
`sure of the weightof the grain in poundsfor a given volume
`(bushel).
`TST WTA=TEST WEIGHT ADJUSTED.The measure of
`the weight of the grain in pounds for a given volume
`(bushel) adjusted for 15.5 percent moisture.
`TSW ADV=TEST WEIGHT ADVANTAGE.The test
`weight advantage of variety #1 over variety #2.
`WIN M %=PERCENT MOISTURE WINS.
`WIN Y %=PERCENT YIELD WINS.
`YLD=YIELD. It is the same as BU ACR ABS.
`
`20
`
`25
`
`40
`
`45
`
`35
`
`60
`
`

`

`5,545,813
`
`9
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`Inbred maize lines are typically developed for use in the
`production of hybrid maize lines. Inbred maize lines need to
`be highly homogeneous, homozygous and reproducible to
`be useful as parents of commercial hybrids. There are many
`analytical methods available to determine the homozygotic
`and phenotypic stability of these inbred lines.
`The oldest and mosttraditional method of analysis is the
`observation of phenotypic traits. The data is usually col-
`lected in field experiments over the life of the maize plants
`to be examined. Phenotypic characteristics most often
`observedare fortraits associated with plant morphology, ear
`and kernel morphology, insect and disease resistance, matu-
`rity, and yield.
`In addition to phenotypic observations, the genotype of a
`plant can also be examined. There are many laboratory-
`based techniques available for the analysis, comparison and
`characterization of plant genotype; amongthese are Isozyme
`Electrophoresis, Restriction Fragment Length Polymor-
`phisms (RFLPs), Randomly Amplified Polymorphic DNAs
`(RAPDs), Arbitrarily Primed Polymerase Chain Reaction
`(AP-PCR), DNA Amplification Fingerprinting (DAF),
`Sequence Characterized Amplified Regions
`(SCARs),
`Amplified Fragment Length Polymorphisms (AFLPs), and
`Simple Sequence Repeats (SSRs) whichare also referred to
`as Microsatellites.
`
`The most widely used of these laboratory techniques are
`Tsozyme Electrophoresis and RFLPs as discussed in Lee,
`M., “Inbred Lines of Maize and Their Molecular Markers,”
`The Maize Handbook, (Springer-Verlag, New York, Inc.
`1994, at 423-432)
`incorporated herein by reference.
`Isozyme Electrophoresis is a useful
`tool
`in determining
`genetic composition, althoughit has relatively low number
`of available markers and the low numberofallelic variants
`among maize inbreds. RFLPs have the advantage of reveal-
`ing an exceptionally high degree of allelic variation in maize
`and the numberof available markers is almostlimitless.
`Maize RFLPlinkage maps have been rapidly constructed
`and wid