United States Patent
`Fullerton
`
`p15
`
`[54]
`
`INBRED MAIZE LINE PH24E
`
`[75]
`
`Inventor: Samuel Gregg Fullerton, Huron, S.
`Dak.
`
`{73] Assignee: Pioneer Hi-Bred International, Inc.,
`Des Moines, Iowa
`
`[21] Appl. No.: 523,660
`
`[22] Filed:
`Sep. 5, 1995
`[SL]
`Tint, CRS eoecessssnsnssensesne A01H 5/00; AO1H 4/00;
`AO1H 1/00; C12N 5/04
`[52] US. Che seesseosenssne 800/200; 800/250; 800/DIG. 56;
`435/240.4; 435/240.49; 435/240.5: 47/58;
`AT/DIG.1
`[58] Field of Search, ooccscssscsccsassssssesussee 800/200, 205,
`800/235, 250, DIG. 56; 435/204.1, 240.4,
`240.47, 240.49, 240.5; 47/58, 58.01, 58.03,
`DIG. 1
`
`US005689034A.
`
`[11] Patent Number:
`
`[45] Date of Patent:
`
`5,689,034
`Nov. 18, 1997
`
`Poehlman et al., (1995) Breeding Field Crop, 4th Ed., Iowa
`State University Press, Ames,
`IA, pp. 132-155 and
`321-344.
`
`Rao, K.V., et al., (1986)“Somatic Embryogenesis in Glume
`Callus Cultures”, Maize Genetics Cooperative Newsletter,
`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. Appi. 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) “Commercial Hybrid Seed Produc-
`tion”, Hybridization of Crop Plants, Ch. 8: 161-176.
`5,276,265=1/1994 Pulllertom 2.0...esccsssensecenneeeers 800/200
`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.
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`FOREIGN PATENT DOCUMENTS
`
`1603390
`
`.
`11/1985 European Pat. Off.
`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”, Planta, 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:
`39-56.
`Green, et al., (1975) “Plant Regeneration From Tissue
`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.
`Meghji, MLR., et al. (1984) “Imbreeding Depression, Inbred
`& Hybrid Grain Yields, and Other Traits of Maize Geno-
`types Representing Three Eras”, Crop Science, vol. 24, pp.
`545-549.
`Phillips, et al. (1988) “Cell/Tissue Culture and In Vitro
`Manipulation”, Corn & Corn Improvement, 3rd Ed., ASA
`Publication, No. 18, pp. 345-387.
`
`Boppenmaier,etal., “Comparsons AmongStrains of Inbreds
`for RFLPs”, Maize Genetics Cooperative Newsletter,
`65:1991, p. 90.
`Coe et al. In Corn and Corn Improvement. Third Edition.
`Sprague et al., eds. Ch. 3: 81-137 ASA-CSSA-SSSAJan.
`1988.
`
`Hallauer et al. In Corn and Corn Improvement. Third
`Edition. Sprague et al., eds. Ch. 8:463-564 ASA-CSSA-S-
`SSA Jan. 1988.
`
`Primary Examiner—Gary Benzion
`Attorney, Agent,
`or Firm—Zarley,
`Voorhees & Sease
`
`McKee, Thomte,
`
`[57]
`
`ABSTRACT
`
`An inbred maize line, designated PH24E, the plants and
`seeds of inbred maize line PH24E, methods for producing a
`maize plant produced by crossing the inbred line PH24E
`with itself or with another maize plant, and hybrid maize
`seeds and plants produced by crossing the inbred line
`PH24E with another maize line or plant.
`
`14 Claims, No Drawings
`
`Inari Exhibit 1052
`Inari Exhibit 1052
`Inari v. Pioneer
`Inari v. Pioneer
`
`

`

`5,689,034
`
`1
`INBRED MAIZE LINE PH24E
`
`FIELD OF THE INVENTION
`
`This invention is in the field of maize breeding, specifi-
`cally relating to an inbred maize line designated PH24E.
`
`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,
`growth rate, 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
`differentplant.
`Plants that have been self-pollinated and selected for type
`for many generations become homozygous at almost all
`gene loci and produce a uniform population of true breeding
`progeny. A cross between two different homozygous lines
`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 same plant, 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 of the ears.
`A reliable method of controlling male fertility in plants
`offers the opportunity for improved plant breeding. Thisis
`especially true for development of maize hybrids, which
`telies upon some sort of male sterility system. There are
`several options for controlling male fertility available to
`breeders, such as: manual or mechanical emasculation (or
`detasseling), cytoplasmic male sterility, genetic male
`sterility, 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
`sufficient isolation 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 CMS inbred 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
`or may not contribute genes that make the hybrid plants
`male-fertile. Usually seed from detasseled fertile maize and.
`
`10
`
`15
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`65
`
`2
`CMSproducedseed ofthe same hybrid are blendedto insure
`that adequate pollen loads are available for fertilization
`whenthe 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 male sterility, 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
`andall 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 which is 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 cells 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 inbred lines
`from breeding populations. Breeding programs combine the
`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
`genotypes, each of which may have one or more desirable
`characteristics that is lacking in the other or which comple-
`mentsthe 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
`way to homogeneouslines as a result of self-pollination and
`selection. Typically in the pedigree method of breeding five
`
`

`

`5,689,034
`
`3
`or more generations of selfing and selection is practiced:
`F,-F,; F,9F4; FFs, 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 that trait. This can be
`accomplished, 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 progenyofthis cross is then mated backto the
`superior recurrentparent followed by selection in the result-
`ant progeny for the desired trait to be transferred from the
`non-recurrent parent. After five or more backcross genera-
`tions 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 of the 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 processin maize, the vigor of the lines decreases.
`Vigor is restored when two different inbred lines are crossed
`to produce the hybrid progeny (F,). An important conse-
`quence of the homozygosity and homogeneity of the inbred
`lines is that the hybrid between a defined pair of inbreds will
`always be the same. Once the 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 inbred lines
`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)
`(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 on stable
`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
`assortment of specific combinationsof alleles at many gene
`loci that results in specific genotypes. Based on the number
`of segregating genes,
`the frequency of occurrence of an
`
`4
`individual with a specific genotype is less than 1 in 10,000.
`Thus, even if the entire genotype of the parents has been
`characterized and the desired genotype is known, only afew
`if any individuals having the desired genotype may be found
`in a large F, or So population. Typically, however, the
`genotype of neither the parents nor the desired genotype is
`knownin 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
`unpredictable, factor in plant breeding. A breeder of ordinary
`skill in the art cannot predict the genotype, how that geno-
`type will interact with various environments or the resulting
`phenotypesof the developing lines, except perhaps in a very
`broad and general fashion. A breeder of ordinary skill in the
`art would also be unable to recreate the same line twice from
`the very same original parents as the breeder is unable to
`direct how the genomes combine or how they will interact
`with the environmental conditions. This unpredictability
`results in the expenditure of large amounts of research
`resources in the developmentof a superior new maize inbred
`line.
`
`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 PH24E. This invention thus
`relates to the seeds of inbred maize line PH24E,to the plants
`of inbred maize line PH24B, and to methods for producing
`a maize plant produced by crossing the inbred line PH24E
`with itself or another maize line. This invention further
`Telates to hybrid maize seeds and plants produced by cross-
`ing the inbred line PH24E with another maize line.
`
`Definitions
`
`In the description and examples that 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: ABSis 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 used in the data
`tables included herein.
`ANT ROT=ANTHRACNOSE STALK ROT
`(Colletotrichum graminicola). A 1 to 9 visual rating indi-
`cating the resistance to Anthracnose Stalk Rot. A higher
`score indicates a higher resistance.
`BAR PLT=BARREN PLANTS.The percent of 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.
`CLN=CORN LETHAL NECROSIS.Synergistic interac-
`tion of maize chlorotic mottle virus (MCMY)in combina-
`tion with either maize dwarf mosaic virus (MDMV-A or
`MDMV-B)or wheat streak mosaic virus (WSMV). A 1 to 9
`
`5
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`35
`
`65
`
`

`

`5,689,034
`
`6
`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 of planting.
`Growing degree units are calculated by the Barger Method,
`where the heat units for a 24-hour period are:
`
`10
`
`opy — (fax. temp. Min. temp.) _ 59
`
`5
`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
`compared to other hybrids on a 1-9 rating scale. A high score
`indicates a hybrid that dries relatively fast while a low score
`indicates a hybrid that dries slowly.
`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 higherresistance.
`DRP EAR=DROPPED EARS. A measure of the number
`of dropped ears per plot and represents the percentage of
`plants that did not drop ears prior to harvest.
`D/T=DROUGHT TOLERANCE.This represents a 1-9
`tating 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 droughttolerance.
`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.
`
`15
`
`20
`
`25
`
`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 percent of 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
`higher resistance.
`EAR MLD=General Ear Mold. Visual rating (1-9 score)
`GLF SPT=Gray Leaf Spot (Cercespora 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
`30
`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=BAR SIZE.A1to 9 visual rating of ear size. The
`A higher score indicates a higher resistance.
`higher the rating the larger the ear size.
`GRN APP=GRAIN APPEARANCE. This is a 1 to 9
`ECB 1LF=EUROPEAN CORN BORER FIRST GEN-
`rating for the general appearance of the shelled grain asit is
`harvested based on such factors as the color of harvested
`ERATION LEAF FEEDING(Osztrinia nubilalis). A 1 to 9
`visual rating indicating the resistance to preflowering leaf
`grain, any mold on the grain, and any cracked grain. High
`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(Osirinia nubilalis).
`with a higher number indicating 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 28C=EUROPEAN CORN BORER SECOND GEN-
`5, and 9 would representvery poor, average, and very good
`yield response, respectively, to increased plant density.
`ERATION(Ostrinia nubilalis). A 1 to 9 visual rating indi-
`HC BLT=HELMINTHOSPORIUM CARBONUM LEAF
`cating post flowering degree of stalk breakage and other
`evidence of feeding by European Corn Borer, Second Gen-
`BLIGHT (Helminthosporium carbonum). A 1 to 9 visual
`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.
`BARS(Ostrinia nubilalis). Dropped ears due to European
`HD SMT=HEAD SMUT (Sphacelotheca reiliana). This
`Corn Borer. Percentage ofplants that did not drop cars 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
`number of plants that emerge on per plot basis for the inbred
`market price per bushel.
`or hybrid.
`INCOME/ACRE. Income advantage of hybrid to be pat-
`ented over other hybrid on per acre basis.
`EYE SPT=Eye Spot (Kabatiella zeae or Aureobasidium
`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.
`INCOME advantage 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 number indicating the hybrid responds well to low
`score indicates a higher resistance.
`plant densities for yield relative to other hybrids. A 1,5, and
`9 would represent very poor, average, and very good yield
`GDU=Growing Degree Units. Using the Barger Heat Unit
`response, respectively, to low plant density.
`Theory, which assumes that maize growth occurs in the
`MDM CPX=MAIZE DWARF MOSAIC COMPLEX
`temperature range 50° F-86° F. and that temperatures
`(MDMV=Maize Dwarf Mosaic Virus and MCDV=Maize
`outside this range slow down growth; the maximum daily
`Chlorotic Dwarf Virus). A 1 to 9 visual rating indicating the
`heat unit accumulation is 36 and the minimum daily heat
`
`35
`
`40
`
`45
`
`50
`
`55
`
`65
`
`

`

`5,689,034
`
`7
`resistance to Maize Dwarf Mosaic Complex. A higher score
`indicates a higher resistance.
`MST=HARVESTMOISTURE.Themoistureis 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 higher resistance.
`PLT HT=PLANT HEIGHT. This is a measure of the
`height ofthe plant from the groundto thetip ofthe tassel in
`inches.
`
`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.Thisis calculated by dry
`weight of tassels collected as shedding commences minus
`dry weight from similar tassels harvested after shedding is
`complete.
`It should be understood that the inbred can, through
`routine manipulation of cytoplasmic or other factors, be
`producedin a male-sterile form. Such embodiments are 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—PLANT POPULATIONofvariety #1=PLANT POPU-
`LATION ADVANTAGEofvariety #1.
`PRM=PREDICTED RELATIVE MATURITY. Thistrait,
`predicted relative maturity, is based on the harvest moisture
`of the grain. The relative 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 on relative maturity of commercial checks.
`RT LDG=ROOT LODGING.Rootlodging is the percent-
`age of plantsthat do not root lodge; 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.Theroot
`lodging advantage of variety #1 over variety #2.
`SCT GRN=SCATTER GRAIN. A 1 to 9 visual rating
`indicating the amountof scatter grain (lack of pollination or
`kernel abortion) on the ear. The higher the score the less
`scatter grain.
`SDG VGR=SEEDLING VIGOR.Thisis the visual rating
`(1 to 9) of the amountof vegetative growth after emergence
`at the seedling stage (approximately five leaves). A higher
`score indicates better vigor.
`SEL IND=SELECTION INDEX. The selection index
`gives a single measure of the hybrid’s worth based on
`information for up to five traits. A maize breeder mayutilize
`his or her ownsetoftraits for the selection index. One of 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.
`
`15
`
`20
`
`25
`
`30
`
`35
`
`50
`
`55
`
`65
`
`8
`SLF BLT=SOUTHERN LEAF BLIGHT
`(Helminthosporium 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). A 1
`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
`(physiological 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 CNTI=NUMBER OF PLANTS. This is the final
`stand or number ofplants 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 stewartii). A 1 to 9
`visual rating indicating the resistance to Stewart’s Wilt. A
`higher score indicates a higherresistance.
`TAS BLS=TASSEL BLAST. A 1 to 9 visual rating was
`used to measure the degree ofblasting (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=TASSEL SIZE. 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 WT=TASSEL WEIGHT.This is the average weight
`of a tassel (grams) just prior to pollen shed.
`TEX EAR=EAR TEXTURE,A 1 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: number of tillers per plot divided
`by number of plants per plot.
`TST WT=TEST WEIGHT (UNADJUSTED). The mea-
`sure of the weightof the grain in pounds for a given volume
`(bushel).
`TST WIA=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.Thetest
`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.
`
`YLD ADV=YIELD ADVANTAGE.Theyield advantage
`of variety #1 over variety #2 as calculated by: YIELD of
`variety #1—YIELD variety #2=yield advantage of variety
`#1,
`
`YLD SC=YIELD SCORE.A 1 to 9 visual rating was used
`to give a relative rating for yield based on plot ear piles. The
`higher the rating the greater visual yield appearance.
`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
`
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`5,689,034
`
`9
`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.
`Theoldest and most traditional 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
`observed are fortraits associated with plant morphology, ear
`and kernel morphology,
`insect and disease resistance,
`maturity, and yield.
`In addition to phenotypic observations, the genotype of a
`plant can also be examined. There are many laboratory-
`based techniques availiable for the analysis, comparison and
`characterization ofplant 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) which are also referred to
`as Microsatellites.
`The most widely used of these laboratory techniques are
`Isozyme 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 too