United States Patent 15
`Martin
`
`AAAAA
`
`US005347081A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,347,081
`Sep. 13, 1994
`
`[54]
`
`INBRED CORN LINE PHKS56
`
`[56]
`
`References Cited
`PUBLICATIONS
`
`[75]
`
`Inventor:
`
`Philip R. Martin, Alburnett, Iowa
`
`[73]
`
`Assignee:
`
`Pioneer Hi-Bred International, Inc.,
`Des Moines, Iowa
`
`[21]
`
`Appl. No.: 6,193
`
`[22]
`
`Filed:
`
`Jan. 19, 1993
`
`[63]
`
`[51]
`
`[52]
`
`[58]
`
`Related U.S. Application Data
`Continuation of Ser. No. 542,352, Jun. 20, 1990, aban-
`doned.
`
`Int. C15 occ cesseesseeees A01H 5/00; AO1H 4/00;
`C12N 5/04
`GUS. CL. ceseecseccessrenessseeseeneeees 800/200; 800/250;
`800/DIG.56; 435/240.4; 435/240.49;
`435/240.5
`Field of Search....... 800/200, 205, 250, DIG. 56;
`435/240.4, 240.49, 240.5
`
`Troyer et al. (1985) Crop Science vol. 25 pp. 695-697.
`Meghji et al. (1984) vol. 24 pp. 545-549.
`Phillips et al (1988) “Cell/Tissue Culture & In Vitro
`Manipulation” by Corn & Corn Improvement. ASA
`Publication #18 3rd Ed. pp. 347-349 & 356-357.
`Poehlman (1987) Breeding Field Crops, AVI Publishing
`Co. Westport, Conn. pp. 237-246.
`
`Primary Examiner—Gary Benzion
`Attorney, Agent, or Firm—Pioneer Hi-Bred
`International, Inc.
`
`ABSTRACT
`[57]
`According to the invention, there is provided an inbred
`corn line, designated PHK56. This invention thus re-
`lates to the plants and seeds of inbred corn line PHK56
`and to methods for producing a corn plant produced by
`crossing the inbred line PHK56 with itself or with an-
`other corn plant. This invention further relates to hy-
`brid corn seeds and plants produced by crossing the
`inbred line PHK56 with another corn line or plant and
`to crosses with related species.
`
`7 Claims, No Drawings
`
`Inari Exhibit 1076
`Inari Exhibit 1076
`Inari v. Pioneer
`Inari v. Pioneer
`
`

`

`1
`
`INBRED CORN LINE PHKS56
`
`5,347,081
`
`This is a continuation of copending application Ser.
`No. 07,542,352 filed on Jun. 20, 1990, now abandoned.
`
`FIELD OF THE INVENTION
`
`This inventionis in the field of corn breeding, specifi-
`cally relating to an inbred corn line designated PHK56.
`BACKGROUNDOF THE INVENTION
`
`The goal of plant breeding is to combine in a single
`variety/hybrid various desirable traits. For field crops,
`these traits may include resistance to diseases and in-
`sects, 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
`fruit size, is important.
`Field crops are bred through techniques that take
`advantageof the plant’s method ofpollination. A plant
`is self-pollinated if pollen from one floweris 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 been self-pollinated and selected for
`type for many generations become homozygousat al-
`most all gene loci and produce a uniform population of
`true breeding progeny. A cross between two homozy-
`gous lines produce a uniform population of hybrid
`plants that may be heterozygous for many gene loci. A
`cross of two plants each heterozygous at a number of
`geneloci will produce a population of hybrid plants that
`differ genetically and will not be uniform.
`Corn plants (Zea mays L.) can be bred by both self-
`pollination and cross-pollination techniques. Corn has
`separate male and female flowers on the same plant,
`located on the tassel and the car, respectively. Natural
`pollination occurs in corn when wind blowspollen from
`the tassels to the silks that protrude from the tops of the
`incipient ears.
`The development of corn hybrids requires the devel-
`opment of homozygous 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 selection 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 moredesir-
`able characteristics that is lacking in the other or which
`complement the other. If the two original parents do
`not provide all of 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
`homogeneous lines as a result of self-pollination and
`selection. Typically in the pedigree method of breeding
`five or more generationsofselfing and selection is prac-
`ticed: Fj—>F2; Fp—>F3; F3—> Fy; Fu—> Fs, etc.
`
`20
`
`25
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`2
`Backcrossing can be used to improve an inbredline.
`Backcrossing transfers a specific desirable trait from
`one inbred or source to an inbred that lacks thattrait.
`This can be accomplished for example byfirst crossing
`a superior inbred (A) (recurrent parent) to a donor
`inbred (non-recurrent parent), which carries the appro-
`priate gene(s) for the trait in question. The progeny of
`this cross is then mated back to the superior recurrent
`parent (A) 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 genera-
`tions with selection for the desired trait, the progeny
`will be heterozygousfor loci controlling the character-
`istic being transferred, but will be like the superior par-
`ent for most or almost all other genes. The last back-
`cross generation would be selfed to give pure breeding
`progeny for the gene(s) being transferred.
`A single cross hybrid corn variety is the cross of two
`inbred lines, each of which has a genotype which com-
`plements the genotype of the other. The hybrid prog-
`eny of the first generation is designated Fj. In the devel-
`opment of hybrids only the F, hybrid plants are sought.
`Preferred F; hybrids are more vigorous than their in-
`bred parents. This hybrid vigor, or heterosis, can be
`manifested in many polygenic traits, including increased
`vegetative growth and increased yield.
`The development of a hybrid corn variety involves
`three steps: (1) the selection of plants from various
`germplasm pools; (2) the selfing of the selected plants
`for several generations to produce a series of inbred
`lines, which, although different from each other, each
`breed true and are highly uniform; and (3) crossing the
`selected inbred lines with unrelated inbred lines to pro-
`duce the hybrid progeny (F1). During the inbreeding
`process in corn, the vigor of the lines decreases. Vigor
`is restored when two unrelated inbred lines are crossed
`to produce the hybrid progeny (F1). An important con-
`sequence of the homozygosity and homogeneity of the
`inbred lines is that the hybrid between any two inbreds
`will always be the same. Once the inbreds that give a
`superior hybrid have been identified, the hybrid seed
`can be reproducedindefinitely as long as the homogene-
`ity 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 (A XB and CxD)and then the two F; hybrids
`are crossed again (A xB) X(C XD). Muchof the hybrid
`vigor exhibited by F, hybridsis lost in the next genera-
`tion (F2). Consequently, seed from hybrid varieties is
`not used for planting stock.
`Corn is an important and valuable field crop. Thus, a
`continuing goal of plant breeders is to develop high-
`yielding corn 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 to envi-
`ronmental stresses. To accomplish this goal, the corn
`breeder must select and develop superior inbred paren-
`tal lines for producing hybrids. This requires identifica-
`tion and selection of genetically unique individuals
`which in a segregating population occuras the result of
`a combination of crossover events plus the independent
`assortment of specific combinations of alleles at many
`gene loci which results in specific genotypes. Based on
`the number of segregating genes, the frequency of oc-
`currence of an individual with a specific genotypeis less
`than 1 in10,000. Thus, even if the entire genotype of the
`
`

`

`5,347,081
`
`4
`
`GDU = (Max. temp. + Min. temp)
`
`__ 50
`
`3
`parents has been characterized and the desired geno-
`type is known, only a few if any individuals having the
`desired genotype may be foundin a large F2 or So popu-
`lation. Typically, however, the genotypeof neither the
`parents northe desired genotype is knownin any detail.
`SUMMARYOF THE INVENTION
`
`According to the invention, there is provided a novel
`inbred corn line, designated PHK56. This invention
`thus relates to the seeds of inbred corn line PHK46, to
`the plants of inbred corn line PHKS6, and to methods
`for producing a corn plant produced by crossing the
`inbred line PHK56 withitself or another corn line. This
`invention further relates to hybrid corn seeds and plants
`produced by crossing the inbred line PHK56 with an-
`other corn line or a related species.
`DEFINITIONS
`
`In the description and examples that follow, a number
`of termsare 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 follow-
`ing definitions are provided:
`ABS=absolute measurement and % MNis percent-
`age of mean of the experiments in which inbred or hy-
`brid was grown unless otherwise defined.
`BAR PLT=BARREN PLANTS.This is the per-
`cent of plants per plot that were not barren (lack ears).
`BRT STK=BRITTLE STALKS. This is a measure
`ofthe stalk breakage nearthe timeofpollination, and is
`an indication of whether a hybrid or inbred would snap
`or break nearthe time of flowering under severe winds.
`Data are presented as percentage of plants that did not
`snap.
`BU ACR=YIELD (BUSHELS/ACRE). Actual
`yield of the grain at harvest adjusted to 15.5% moisture.
`CLD TST=COLDTEST.This is the percentage of
`kernels that germinate under cold soil conditions. ABS-
`==absolute measurement and % MNis percentage of
`mean of the experiments in which inbred or hybrid was
`grown.
`COB SC=COB SCORE.The cobscoreis a rating of
`how well the grain is shelled off the cob and how badly
`the cob is broken up going through the combine. Thisis
`given as a I to 9 score with 9 being very good. A high
`score indicates that the grain shells off of the cob well,
`and the cob does not break.
`DRP EAR=DROPPED EARS.This is a measure
`of the number of dropped ears per plot and represents
`the percentage of plants that did not drop ears prior to
`harvest.
`EAR HT=EAR HEIGHT.Theear height is a mea-
`sure from the ground to the top developed ear node
`attachment and is measured in inches.
`EAR SZ=EARSIZE. A 1 to 9 visual rating of ear
`size. The higher the rating the larger the ear size.
`EST CNT=EARLY STAND COUNT.This is a
`measure of the stand establishment in the spring and
`represents the numberof plants that emerge on a per
`plot basis for the inbred or hybrid.
`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 per-
`cent of the plants shedding pollen and is measured from
`the time of planting. Growing degree units are calcu-
`lated by the Barger Method, where the heat units for a
`24-hour period are:
`
`3
`
`20
`
`25
`
`35
`
`40
`
`45
`
`50
`
`35
`
`60
`
`65
`
`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
`GDwUsto reach various stages of plant development.
`GDU SLK=GDUTOSILK.The numberof grow-
`ing 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.
`GRN QUL=GRAIN QUALITY.This is a 1 to 9
`rating for the general quality of the shelled grain asit is
`harvested based on such factors as the color of the
`harvested grain, any mold on the grain, and any cracked
`grain. High scores indicate good grain quality.
`MST=HARVEST MOISTURE. The moisture is
`the actual percentage moisture of the grain at harvest.
`PLT HT=PLANT HEIGHT.This is a measure of
`the height of the plant from the groundto the tip of the
`tassel in inches.
`POL SC=POLLEN SCORE.A 1 to 9 visual rating
`indicating the amount of pollen shed. The higher the
`score the more pollen shed.
`PRM=PREDICTED RM.Thistrait, predicted rela-
`tive maturity (RM), is based on the harvest moisture of
`the grain. The relative maturity rating is based on a
`knownset of checksand utilizes standard linear regres-
`sion analyses and is referred to as the Minnesota Rela-
`tive Maturity Rating System.
`RT LDG=ROOT LODGING.Rootlodgingis the
`percentage of plants that do not root lodge; plants that
`lean from the vertical axis at an approximately 30° angle
`or greater would be counted as root lodged.
`SCT GRN=SCATTER GRAIN. A 1 to 9 visual
`rating indicating the amount of scatter grain (lack of
`pollination or kernel abortion) on the ear. The higher
`the score the less scatter grain.
`SDG VGR=SEEDLING VIGOR.This is the vi-
`sual rating (1 to 9) of the amount of 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 upto five traits. A corn breeder may
`utilize his or her ownset oftraits for the selection index.
`Oneofthetraits that is almost always includedis yield.
`The selection index data presented in the tables repre-
`sent the mean value averaged across testing stations.
`STA GRN=STAY GREEN.Stay green is the mea-
`sure of plant health near the time of black layer forma-
`tion (physiological maturity). A high score indicates
`better late-season plant health.
`STK CNT=NUMBER OF PLANTS.This is the
`final stand or numberof plants perplot.
`STK LDG=STALK LODGING.This is the per-
`centage of plants that did not stalk lodge (stalk break-
`age) as measured by either natural lodging or pushing
`the stalks and determining the percentage of plants that
`break below the ear.
`TAS BLS=TASSEL BLAST.A I to 9 visual rating
`was used to measure the degreeofblasting (necrosis due
`to heat stress) of the tassel at time of flowering. A 1
`would indicate a very high level of blasting at time of
`flowering, while a 9 would havenotassel blasting.
`
`

`

`5,347,081
`
`10
`
`15
`
`20
`
`30
`
`35
`
`5
`6
`ECB 1LF=European Corn Borer First Brood (Os-
`TAS SZ=TASSELSIZE.A 1 to 9 visual rating was
`used to indicate the relative size of the tassel. The
`trinia nubilalis): Visual rating (1-9 score) of pre-flower-
`higher the rating the larger the tassel.
`ing leaf feeding by European Corn Borer. A “1”is very
`susceptible and a “9” is very resistant.
`TAS WT=TASSEL WEIGHT.This is the average
`weight of a tassel (grams) just prior to pollen shed.
`DETAILED DESCRIPTION OF THE
`TEX EAR=EAR TEXTURE.AIto 9 visual rating
`INVENTION
`was used to indicate the relative hardness (smoothness
`Inbred corn line PHK56is a yellow, dent corn inbred
`of crown) of mature grain. A 1 would be very soft
`that provides an acceptable male parental line in crosses
`(extreme dent) while a 9 would be very hard (flinty or
`very smooth crown).
`for producing first generation F1 corn hybrids. PHK56
`TILLER=TILLERS. A count of the number of
`is best adapted to the Central Corn Belt of the United
`Siates. The inbred can be used to produce hybrids from
`tillers per plot
`that could possibly shed pollen was
`approximately 106-118 relative maturity based on the
`taken. Data is given as percentage oftillers: number of
`Minnesota Relative Maturity Rating System for harvest
`tillers per plot divided by numberofplants per plot.
`TST WT=TEST WEIGHT UNADJUSTED.The
`moisture of grain. PHK56 would make a good male
`because it is a good pollinator with good pollen yield. In
`measure of the weight of the grain in pounds for a given
`hybrid combinations PHK56 provides high yields, has
`volume (bushel).
`TST WTA=TEST WEIGHT ADJUSTED. The
`low grain moisture at maturity and performs under
`stress as well as good conditions. It also has good roots,
`measure of the weight of the grain in poundsfor a given
`low ear placement, and gray leaf spot tolerance.
`volume (bushel) adjusted for percent moisture.
`YLD=YIELD.It is the same as BU ACR ABS.
`The inbred has shown uniformity and stability within
`the limits of environmental influencefor all the traits as
`YLD SC=YIELD SCORE.A 1 to 9 visual rating
`described in the Variety Description Information
`wasused to givearelative rating for yield based on plot
`(Table 1) that follows. Most of the data in the Variety
`ear piles. The higher the rating the greater visual yield
`25
`appearance.
`Description Information was collected at Johnston,
`Iowa. The inbred has been self-pollinated and ear-
`MDM CPX=Maize Dwarf Mosaic Complex
`rowed a sufficient number of generations with careful
`(MDMV=Maize
`Dwarf Mosaic
`Virus
`&
`attention paid to uniformity of plant type to ensure and
`MCDV =Maize Chlorotic Dwarf Virus): Visual rating
`(1-9 score) where a “1” is very susceptible and a “9” is
`phenotypic stability. The line has been increased both
`by hand and in isolated fields with continued observa-
`very resistant.
`COM SMT=Common Smut (Ustilago maydis): Per-
`tion for uniformity. No variant traits have been ob-
`centage of plants that did not have infection.
`served or are expected in PHK56.
`SLF BLT=Southern Leaf Blight (Bipolaris maydis,
`Inbred corn line PHK56,being substantially homozy-
`Helminthosporium maydis): Visual rating (1-9 score)
`gous, can be reproduced by planting seeds ofthe line,
`growingthe resulting corn plants underself-pollinating
`where a “1” is very susceptible and a “9”is very resis-
`tant.
`or sib-pollinating conditions with adequate isolations,
`and harvesting the resulting seed, using techniques fa-
`miliar to the agricultural arts.
`TABLE1
`VARIETY DESCRIPTION INFORMATION
`INBRED = PHK56
`Region Best Adapted:
`Central Corn Belt
`
`NLF BLT=Northern Leaf Blight (Exserohilum tur-
`cicum, H. turcicum): Visual rating ( 1-9 score ) where a
`“1” is very susceptible and a “9” is very resistant.
`COM RST=Common Rust (Puccinia sorghi): Visual
`rating 1-9 score) where a “1” is very susceptible and a
`“9” is very resistant.
`EYE SPT=Eyespot (Kabaiiella zeae): Visual rating
`(1-9 score) where a “1”is very susceptible and a “9”is
`very resistant.
`GLF SPT=Gray Leaf Spot (Cercospora zeae-may-
`dis): Visual rating (1-9 score) where a 1 is very suscepti-
`ble and a “9”is very resistant.
`STW WLT=Stewart’s Wilt (Erwinia stewartii): Vi-
`sual rating (1-9 score) where a “1” is very susceptible
`and a “9” is very resistant.
`(reiliana): Percentage of
`HD SMT=Head Smut
`plants that did not have infection.
`EAR MLD=General Ear Mold: Visual rating (1-9
`score) where a “1”is very susceptible and a “9”is very
`resistant. This is based on overall rating for ear mold of
`mature ears without determining specific mold organ-
`ism, and may not be predictive for a specific ear mold.
`ECB DPE=Dropped ears due to European Corn
`Borer (Ostrinia nubilalis): Percentage of plants that did
`not drop ears under second brood corn borerinfesta-
`tion.
`
`ECB 2SC=European Com Borer Second Brood
`(Ostrinia nubilalis): Visual rating (1-9 score) of post
`flowering damagedueto infestation by European Corn
`Borer. A “1” is very susceptible and a “9” is very resis-
`tant.
`
`Type: DENT
`
`45
`
`50
`
`35
`
`60
`
`65
`
`A. Maturity: Average across maturity zones. Zone : 0
`Heat Unit Shed: 1420
`Heat Unit Silk: 1460
`No. Reps: 59
`
`[Max. Temp.(=86° F.) +
`Min. Temp(2 50° F.)]*
`7
`HEAT UNITS =
`*If maximum is greater than 86 degrees fahrenheit, then 86 is used and if minimum
`is less than 50, then 50 is used. Heat units accumulated daily and can notbe less than
`0.
`
`— 50
`
`B. Plant Characteristics:
`Plant height (to tassel tip): 216 cm
`Length of top ear internode: 12 cm
`Numberof ears per stalk: Single
`Ear height (to base of top ear): 82 cm
`Numberoftillers: None
`Cytoplasm type: Normal
`C. Leaf:
`Color: (WF9) Medium Green
`Angle from Stalk: 30-60 degrees
`
`

`

`5,347,081
`
`8
`I (intermediate): Would generally represent a score of
`4-5,
`R (Resistant): Would generally represent a score of 6-7.
`H (Highly Resistant): Would generally represent a
`score of 8-9. Highly resistant does not imply the
`inbred is immune.
`
`J. Variety Most Closely Resembling:
`Character
`Inbred
`Maturity
`PHW43
`Usage
`PHW43
`
`Data for Items B, C, D, E, F, and G is based primarily
`on a maximum of two reps from Johnston, Iowa grown
`in 1988, plus description information from the maintain-
`ing station.
`ELECTROPHORESIS RESULTS
`
`Isozyme Genotypes for PHK56
`
`7
`Marginal Waves: (OH7L) Many
`Number of Leaves (mature plants): 18
`Sheath Pubescence: (WF9) Medium
`Longitudinal Creases: (PA11) Many
`Length (Ear nodeleaf): 72 cm
`Width (widest point, ear node leaf): 10 cm
`D. Tassel:
`Numberlateral branches: 6
`Branch Angle from central spike: 30-40 degrees
`Pollen Shed: Heavy based on Pollen Yield Test (107% 10
`of experiment means)
`Peduncle Length (top leaf to basal branches): 25 cm
`Anther Color: Yellow
`Glume Color: Green
`E. Ear (Husked Ear Data Except When Stated Other- 15
`wise):
`Length: 17 cm
`Weight: 142 gm
`Mid-point Diameter: 42 mm
`Silk Color: Pink
`Husk Extension (Harvest stage): Medium (Barely Cov-
`ering Ears)
`Husk Leaf: Short (<8 cm)
`Taper of Ear: Average
`Position of Shank (dry husks): Horizontal
`Kernel Rows: Slightly Curved, Distinct Number = 16
`Husk Color (fresh): Light Green
`Husk Color (dry): Buff
`Shank Length: 16 cm
`Shank (No.of internodes): 8
`F, Kernel (Dried):
`Size (from ear mid-point)
`Length: 11 mm
`Width: 8 mm
`Thick: 4 mm
`Loci
`ACP1
`Shape Grade (% rounds): 20-40 30% medium round
`ADH1
`based on Parent Test Data)
`CAT3
`Pericarp Color: Colorless
`DIAI
`Aleurone Color: Homozygous Yellow
`GOT1
`GOT2
`Endosperm Color: Yellow
`GOT3
`Endosperm Type: Normal Starch
`IDH1
`Gm Wt/100 Seeds (unsized): 25 gm
`IDH2
`G. Cob:
`MDHI
`MDH2
`Diameter at mid-point: 25 mm
`MDH3
`Strength: Strong
`MDH4
`Color: Red
`MDHS5
`H.Diseases:
`MMM
`PGM1
`Corn Lethal Necrosis (MCMV =Maize Chlorotic Mot-
`PGM2
`tle Virus and MDMV=Maize Dwarf Mosaic Virus): 59
`00
`PGD1
`Intermediate
`PGD2
`Anthracnose Stalk Rot (C. Graminicola): Intermediate
`PHI
`N. Leaf Blight (4. turcicum): Intermediate
`Carbonum Leaf Blight (Z. carbonum): Susceptible
`Eye Spot (K. zeae): Intermediate
`Gray Leaf Spot (C. zeae): Intermediate
`Goss’s Wilt (C. nebraskense): Resistant
`Common Smut (U. maydis): Resistant
`Head Smut(S. reiliana): Highly Resistant
`Fusarium Ear Mold (F. moniliforme): Resistant
`I. Insects:
`European Corn Borer-1 Leaf Damage (Pre-flowering):
`Intermediate
`European Corn Borer-2 (Post-flowering): Susceptible
`The above descriptions are based on a scale of 1-9,
`being highly susceptible, 9 being highly resistant.
`S (Susceptible): Would generally represent a score of
`1-3.
`
`Isozyme data were generated for inbred corn line
`PHK56 according to the procedures described in
`Stuber, C. W., Wendel, J. F., Goodman, M. M., and
`Smith, J. S. C., “Techniques and Scoring Procedures
`for Starch Gel Electrophoresis of Enzymes from Maize
`(Zea mays L.)”, Technical Bulletin No. 286, North Car-
`olina Agricultural Research Service, North Carolina
`State University, Raleigh, N.C. (1988).
`.
`The data in Table 2 compares PHK56 with its par-
`ents, PHG47 and PHG35.
`TABLE2
`ELECTROPHORESIS RESULTS FOR PHK56
`
`AND ITS PARENTS PHG47 AND PHG35
`PARENTS
`PHG47
`PHG35
`4
`
`3
`
`20
`
`25
`
`3Qo
`
`35
`
`45
`
`55
`
`60
`
`1 65
`
`PHKS6
`4
`
`—ee
`
`—aWORNNAWAHLHEHSHPhwwPp
`
`AN
`
`—PUWHWOLNNAADAARHLAAHOUAHL
`
`INDUSTRIAL APPLICABILITY
`
`This invention also is directed to methods for produc-
`ing a corn plant by crossing a first parent corn plant
`with a second parent corn plant wherein the first or
`second parent corn plant is an inbred corn plant from
`the line PHK56. Further, both first and second parent
`corn plants can come from the inbred corn line PHK56.
`Thus, any such methods using the inbred corn line
`PHK56are part of this invention: selfing, backcrosses,
`hybrid production, crosses to populations, and the like.
`All plants produced using inbred corn line PHK56 as a
`parent are within the scope of this invention. Advanta-
`geously, the inbred corn line is used in crosses with
`
`

`

`5,347,081
`
`10
`
`—_ 5
`
`20
`
`9
`10
`other, different, corn inbreds to producefirst generation
`line PHK56 is presented for the key characteristics and
`traits.
`(F)) corn hybrid seeds and plants with superior charac-
`teristics.
`Table 3A compares inbred PHK56 to PHG47.
`PHG47is a parent of PHK56. The results show that
`As used herein, the terms “plant and plant parts”
`PHK56hashigher grain yield than PHG47. PHK5S6is a
`include plant cells, plant protoplasts, plant cell tissue
`taller inbred with higher ear placement and flowers
`culture from which corn plants can be regenerated,
`(GDU SHD and GDU SLK)
`later than PHG47.
`plantcalli, plant clumps, and plantcells that are intact in
`PHK56 has better stay green, more resistance to ear
`plants or parts of plants, such as embryos, pollen, flow-
`mold, gray leaf spot, and first and second brood Euro-
`ers, kernels, ears, cobs, leaves, husks, stalks, roots, root
`pean corn borer, but is slightly more susceptible to
`tips, anthers, silk and the like.
`common rust and northern corn leaf blight
`than
`Tissue culture of corn is described in European Pa-
`PHG47.
`tent Application, publication 160,390,
`incorporated
`The results in Table 3B compare PHK5S6toits other
`herein by reference. Corn tissue culture procedures are
`parent, PHG35. PHK56 yields more,
`is taller with
`also described in Green and Rhodes, “Plant Regenera-
`lower ear placement, and flowers (GDU SHD and
`tion in Tissue Culture of Maize,” Maize for Biological
`GDU SLK)earlier than PHG35. PHK56 has better
`Research (Plant Molecular Biology Association, Char-
`seedling vigor and slightly lower early stand count
`lottsville, Va. (1982, at 367-372). Thus, another aspect
`compared to PHG35. PHK56 showsslightly better
`of this invention is to provide cells which upon growth
`resistance to ear mold and northern corn leaf blight, is
`and differentiation produce the inbred line PHK56.
`similar in resistance to first brood European corn borer,
`The utility of inbred line PHK56 also extends to
`and is more susceptible to second brood European corn
`crosses with other species. Commonly, suitable species
`borer compared to PHG35.
`will be of the family Graminaceae, and especially of the
`The data in Table 3C show that PHK56 has higher
`genera Zea, Tripsacum, Coix, Schlerachne, Polytoca,
`yield and test weight but lower grain moisture at matu-
`Chionachne, and Trilobachne, of the tribe Maydeae. Of
`25
`rity than PHN82. PHK56isataller inbred with higher
`these, Zea and Tripsacum, are most preferred. Poten-
`ear placement and flowers (GDU SHD and GDU
`tially suitable for crosses with PHK56 may bethe vari-
`SLK)earlier than PHN82. PHK56 has better seedling
`ous varieties of grain sorghum, Sorghum bicolor (L.)
`Moench.
`vigor but lower early stand establishment than PHN82.
`The pollen yield is greater and tassel size larger for
`Corn is used as human food, livestock feed, and as
`PHK56 than PHN8&2. PHK56 has better stalks but
`raw material in industry. The food uses of corn, in addi-
`poorer roots, is more resistant to gray leaf spot, and
`tion to human consumption of corn kernels, include
`more susceptible to commonrust and northern corn leaf
`both products of dry- and wet-milling industries. The
`blight than PHN82.
`principal products of corn dry milling are grits, meal
`Table 3D showsthat PHK56 and PHV78 havesimi-
`and flour. The corn wet-milling industry can provide
`lar yield. PHK‘56 is shorter with lower ear placement
`corn starch, corn syrups, and dextrose for food use.
`and flowers (GDU SHD and GDU SLK)earlier than
`Corn oil is recovered from corn germ, which is a by-
`PHV78. PHK56 has less pollen yield and a smaller
`product of both dry- and wet-milling industries.
`tassel compared to PHV78. PHK56is moreresistant to
`Corn, including both grain and non-grain portions of
`stalk lodging and ear mold but more susceptible to
`the plant,
`is also used extensively as livestock feed,
`northern corn leaf blight and first brood European corn
`primarily for beefcattle, dairy cattle, hogs, and poultry.
`borer than PHV78.
`Industrial uses of corn are mainly from corn starch
`Table 3E results show that PHK56 and PHW43 have
`from the wet-milling industry and corn flour from the
`similar yield and plant and ear height. PHK56 has better
`dry-milling industry. The industrial applications of corm
`seedling vigor and similar early stand establishment
`starch and flour are based on functional properties, such
`compared to PHW43. PHK56 flowers (GDU SHD and
`as viscosity, film formation, adhesive properties, and
`GDUSLK)earlier than PHW43. PHK56 has better ear
`ability to suspend particles. The corn starch and flour
`mold resistance, similar first brood European corn
`have application in the paper and textile industries.
`borer resistance, but is slightly more susceptible to sec-
`Other industrial uses include applications in adhesives,
`ond brood European corn borer than PHW43.
`building materials, foundry binders, laundry starches,
`The results in Table 4A compare PHK56 to PHN82
`explosives, oil-well muds, and other mining applica-
`crossed to the same inbred testers. The results show that
`tions.
`PHK‘56 hybrids yield less and have lower test weight
`Plant parts other than the grain of corn are also used
`and grain harvest moisture than PHN82 hybrids. The
`in industry. Stalks and husks are made into paper and
`PHK56 and PHN82 hybrids have similar plant and ear
`wallboard and cobs are used for fuel and to make char-
`height and flower at approximately the same time.
`coal.
`PHK56 hybrids have average stay green and are more
`The seed of inbred corn line PHK56, the plant pro-
`susceptible to stalk and root
`lodging compared to
`duced from the inbred seed, the hybrid corn plant pro-
`PHN82 hybrids.
`duced from the crossing of the inbred, hybrid seed, and
`Table 4B compares PHK56 to PHV78crossed to the
`various parts of the hybrid corn plant can be utilized for
`same inbred testers. The PHK56 hybrids have higher
`human food, livestock feed, and as a raw material in
`yield and test weight and lower grain moisture at matu-
`industry.
`rity than the PHV78 hybrids. PHK56 hybrids are
`shorter with lower ear placement and flower (GDU
`SHD)earlier than PHV78 hybrids. The PHK56 hybrids
`have better stalk and root lodging resistance than the
`PHV78 hybrids.
`Theresults in Table 4C compare PHK56 to PHW43
`crossed to the same inbred testers. The hybrids are
`
`Inbred and Hybrid Performance of PHK56
`in the examples that follow thetraits and characteris-
`tics of inbred corn line PHK56 are given as a line and in
`hybrid combination. The data collected on inbred corn
`
`35
`
`65
`
`EXAMPLE
`
`

`

`5,347,081
`
`5
`
`YEAR
`TOTAL SUM
`
`REGION
`
`VAR
`#
`1
`2
`LOcS
`DIFF
`PROB
`
`12
`11
`and flowers (GDU SHD) muchearlier than 3180. The
`similar for yield and test weight but the PHK56 hybrids
`have lowergrain moisture at maturity than the PHW43
`PHK‘56 hybrid has similar stalks, is more susceptible to
`root lodging, and has lowerseedling vigor compared to
`hybrids. The PHK56 hybrids havebetter early stand
`3180.
`establishment than the PHW43 hybrids.
`Tables 5-8 compare PHK56 hybrids to Pioneer
`Table 7 compares a PHK56 hybrid with 3344. The
`Brand Hybrids 3362, 3180, 3344, and 3467, respectively.
`PHKS6 hybrid is lower yielding, has higher test weight,
`Each hybrid has a parent in common with the PHK56
`and has less grain moisture at maturity than 3344. The
`hybrid other than PHK56. The hybrids are adapted to
`PHK56 hybrid is shorter with lower ear placement and
`much of the same area as the PHKS56 hybrids. Table 5
`flowers (GDU SHD)earlier than 3344. The PHK56
`compares a PHK56 hybrid with 3362. The PHK56
`hybrid has better stalks and roots than 3344.
`hybridis slightly lower yielding, has similar test weight,
`Table 8, comparing a PHK56 hybrid to 3467, shows
`and has lowergrain harvest moisture compared to 3362.
`the PHK456 hybrid has higher yield, lower test weight,
`The PHK56 hybrid is shorter with lower ear placement
`and less grain harvest moisture than 3467. The PHK56
`and flowers (GDU SHD)earlier than 3362. The PHK56
`hybrid is shorter but has higher ear placement and flow-
`ers (GDU SHD)earlier than 3467. The PHK56 hybrid
`hybrid has better seedling vigor and early stand count 15
`than 3362. The PHK56 hybrid has better stalk lodging
`has better stalk lodging resistance b