Abstract:
According to the invention, there is provided an inbred corn line, designated CG00637. This invention thus relates to the plants and seeds of inbred corn line CG00637 and to methods for producing a corn plant produced by crossing the inbred line CG00637 with itself or with another corn line. This invention further relates to hybrid corn seeds and plants produced by crossing the inbred line CG00637 with another corn line.

Description:
This application is a continuation, of application Ser. No. 07/808,397, filed Dec. 16, 1991, now abandoned. 
    
    
     FIELD OF THE INVENTION 
     This invention is in the field of hybrid corn (Zea mays L.) plant breeding, specifically relating to an inbred corn line designated CG00637. 
     BACKGROUND OF THE INVENTION 
     Of all the crops produced by U.S. farmers, corn is the crop that has the most economic value. Corn is utilized as livestock feed, as a basis for human consumption, as raw material for industry and as raw material for the production of ethanol. The primary use of farmer produced field corn is for livestock feed. This includes feed for hogs, beef cattle, dairy cows and poultry. 
     Human consumption of corn includes direct consumption of sweet corn and as snacks after extruder cooking, ground corn eaten as grits, corn meal and corn flour. Corn oil is also used as a high grade cooking oil, salad oil or in margarine. Corn is used in the production of some starches and syrups. Another important use is in the production of sweeteners used in soft drinks. 
     The wet-milling and dry-milling processes also produce corn starch and corn flour that have applications in industry. Some of these uses include building materials, the paper industry, textiles and starches. 
     The seed of inbred corn line CG00637, the plant produced by the inbred seed, the hybrid corn plant produced from the crossing of the inbred, hybrid seed, and various parts of the inbred and hybrid corn plant can be utilized for human food, livestock feed, and as a raw material in the industry. 
     The major reasons for the economic importance of corn and the large acreages planted to the crop are the hybridization of the corn plant and the continued improvement, by researchers, of the genetic stock that is used to produce the seed grown by farmers. This process has been on-going since its beginning in the early pan of the century. The average bushel per acre yield for the American farmer has gone from around 30 in the middle of the 1930&#39;s (before hybrids became dominant) to the present average of close to 120. While not all of this four-fold increase can be attributed to genetic improvement (availability of relatively cheap nitrogen and improvements in farming practices are two other components), a good share of it can. 
     Corn is easily hybridized because of the physical distance between the tassel (male part) and the ear (female part). The method of hybridization first involves the development of inbred lines. Inbred corn lines are considered to be homozygous, or, in essence, genetically the same from generation to generation. They are produced by taking the pollen from one plant and putting it only on the ear of that same plant. The resulting seed is grown, selections for uniformity and improved agronomic characteristics are made and the process is repeated until the seeds from the ears of the plants produce homozygous plants and the line is pure. A hybrid is then produced by crossing one inbred with another, genetically different, inbred. The crossing consists of taking the pollen from one inbred and putting it on the ear of the other inbred. 
     The seed from the crossing of two inbred lines is a first generation hybrid and is called an F 1 . The F 1  of commercially viable hybrids have better yields, and other important characteristics, than either of the parents. This process is called hybrid vigor or heterosis. In succeeding generations (F 2 , F 3 , etc.) this heterosis is markedly reduced, making it economically justifiable for the farmer to go back to the seed company and obtain F 1  seed each year. As a result, the hybrid corn seed industry benefits both farmers and producers of hybrid corn seed. 
     The invention of new inbred lines and of new hybrids is extremely important to the companies in the hybrid seed corn industry that have investments in research. Much effort is given to the research and development of these inbreds and hybrids. The breeding and selection of inbred lines to be used as both seed parents and/or pollen parents and which when crossed to other inbred lines produce F 1  hybrid seed, which when planted, will produce plants that have characteristics that a farmer desires is a highly specialized skill. It involves many years of inbreeding, skilled selection, correct statistical testing, and decision making. 
     SUMMARY OF THE INVENTION 
     According to the invention, there is provided a novel inbred corn line, designated CG00637. This invention thus relates to the seeds of inbred corn line CG00637, to the plants of inbred corn line CG00637 and to methods for producing a corn plant produced by crossing the inbred line CG00637 with itself or another corn line. This invention further relates to hybrid corn seeds and plants produced by crossing the inbred line CG00637 with another corn line. 
     DEFINITIONS 
     This section will outline the definitions of terms used herein. 
     Yield (Bushels/Acre). The yield in bushels/acre is the actual yield of the gain at harvest adjusted to 15.5% moisture. 
     Percent Moisture. The moisture is the actual percentage moisture of the gain at harvest adjusted for test-weight. 
     Percent Erect. The percent erect is the percentage of plants that are still erect or standing at harvest. 
     Harvest Roots. Harvest roots is a visual rating. It is based on the number of plants that are root-lodged, i.e.; leaning from the vertical axis at an approximate 30° angle or greater. The ratings range from 1 to 9. A rating of 1 equals no plants root-lodged and a rating of 9 equals all plants root-lodged. 
     Percent Dropped Ears. The percent dropped ears is the percentage of plants that dropped (lost) their ears before harvest. 
     Percent Barren Plants. The percent barren plants is the percentage of plants that were barren (lacking ears). 
     Intactness. Intactness is a visual rating. It is based on the percentage of leaf and stalk matter remaining above the top ear at harvest. The ratings range from 1 to 9. A rating of 1 equals all matter remaining (intact) and a rating of 9 equals all matter gone or the stalk broken over just above the ear. 
     Percent Green. The percent green is the percentage of the total ear, leaf and stalk matter still green at the time of data collection, approximately physiological maturity. 
     Standard Index. Standard index gives a single measure of a hybrid&#39;s worth based on information for six traits. A corn breeder may utilize his or her own set of traits for the selection index. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Inbred corn line CG00637 is a yellow dent corn with superior characteristics and provides an excellent parental line in crosses for producing first generation (F 1 ) hybrid corn. Inbred corn line CG00637 was selected for uniformity and agronomic traits, from the cross of Pioneer Hybrid 3906 by Pioneer Hybrid 3732, commercially available from Pioneer Hi-Bred International, by selfing and using standard pedigree ear-row selection. Selfing and selection were practiced within the above F1 cross for eight generations in the development of CG00637 at Kaunakakai, HI and Owatonna, MN. The inbred was evaluated further as a line and in numerous crosses by the Owatonna Research Station and other research stations across Michigan, New York, North Dakota, Pennsylvania, Wisconsin and Ontario, Canada. Thus the line was evaluated for general and specific combining ability. One particular cross showed outstanding performance in research testing across several research stations and was tested extensively over six years of testing. 
     The inbred is adapted to the northern corn belt and can be used advantageously in producing hybrids that are from approximately 85 day relative maturity to 95 day relative maturity based on the Minnesota Relative Maturity Rating System for harvest moisture of the grain. The inbred is a good female parent for use in commercial hybrid seed corn production with good seed yield, good seed quality and a very desirable distribution of sized seed. The inbred could also be used as a male parent in the production of commercial hybrids. 
     The inbred has shown relative uniformity and stability for all traits as described in the following variety description information. It has been self-pollinated and ear-rowed a sufficient number of generations with careful attention paid to uniformity of plant type to insure relative homozygosity and phenotypic stability. The line has been increased by hand pollination and in isolated fields with continued observations for uniformity. No particular variant traits have been observed or are expected in CG00637. 
     Inbred corn line CG00637 can be compared to the public inbred CM105. The characteristics of CG00637 versus CM105 are summarized below (based on data collected at Morris, Minn.): 
     
         ______________________________________          CG00637   CM105______________________________________MATURITYDays from emergence to 50%            68          68of plants in silkHeat units from emergence to            1330        133150% of plants in silkDays from emergence to 50%            66          64of plants shedding pollenHeat units from emergence to            1297        122050% of plants shedding pollenPLANTCHARACTERISTICSPlant height to tassel tip (cm)            162         191Ear height to top ear node            54          57(cm)Length of top ear internode            15          14(cm)Ears per stalk   Single      SingleNumber of tillers            None        NoneAnthocyanin in brace roots            Present     PresentCytoplasm type   Normal      NormalLEAFColor            Medium green                        Dark greenAngle from stalk (degrees)            30-40       30-40Sheath pubescence            Medium      HeavyMarginal waves   Few         ManyLongitudinal creases            Few         FewWidth of ear node leaf at            7           7widest point (cm)Length of ear node leaf (cm)            70          79Number of leaves above the            5           6ear nodeTASSELNumber of lateral branches            4           4Branch angle from central            30-40       30-40spike (degrees)Peduncle length (cm)            6           8Pollen shed      Medium      MediumAnther color     Purple      PurpleGlume color      Green       GreenGlume bars       Absent      AbsentEAR (Husked Ear Data at12.5% Kernel Moisture)Length (cm)      13          13Mid-point diameter (mm)            41          39Weight (gm)      96          86Kernel rows      14, distinct,                        14, distinct,            slightly curved                        straightSilk color       Green       SalmonHusk color (fresh)            Light green Light greenHusk color (dry) Buff        BuffHusk extension   Medium (barely                        Medium (barely            covering ear)                        (covering ear)Husk leaf        Short (&lt;8 cm)                        Short (&lt;8 cm)Shank Length (cm)            8           9Shank (no. of internodes)            6           7Position of shank (dry husks)            Horizontal  HorizontalTaper            Slight      SlightKERNEL(at 12.5% kernel moisture)Size (kernels taken from ear            10 mm long, 10 mm long,mid-point)       8 mm wide,  8 mm wide,            4 mm thick  5 mm thickShape grade (% rounds)            20-40       20-60Pericarp color   Variegated  VariegatedAleurone color   Homozygous, Homozygous,            white       whiteEndosperm color  Yellow      YellowEndosperm type   Normal starch                        Normal starchGram weight/100 seeds            21          24(unsized sample)Test weight (pounds)            55          60COBDiameter at midpoint (mm)            23          25Strength         Strong      StrongColor            Red         RedDisease reaction information for CG00637 are given below:Anthracnose leaf blight             Moderately ResistantCommon smut       ResistantWheat streak mosaic             Resistant______________________________________ 
    
     Heat units calculations are derived by using the following formula: Heat Units equals [Daily Maximum Temperature (&lt;86° F.) plus Daily Minimum Temperature (&gt;50° F.)] divided by 2 minus 50° F. 
     This invention is also directed to methods for producing a corn plant by crossing a first parent corn plant with a second parent corn plant wherein the first or second corn plant is the inbred corn plant from the line CG00637. Further both first and second parent corn plants may be from the inbred line CG00637. Thus, any methods using the inbred corn line CG00637 are part of the invention: backcrosses, hybrid breeding, and crosses to populations. Any plants produced using inbred corn line CG00637 as a parent are within the scope of this invention. Advantageously, the inbred corn line CG00637 is used in crosses with other corn varieties to produce first generation (F 1 ) corn hybrid seed and plants with superior characteristics. 
     As used herein, the term &#34;plant&#34; includes plant cells, plant protoplasts, plant cell of tissue culture from which corn plants can be regenerated, plant calli, plant clumps, and plant cells that are intact in plants or pans of plants such as pollen, flowers, kernels, ears, cobs, leaves, husks, stalks, and the like. Thus another aspect of this invention is to provide for cells which upon growth and differentiation produce the inbred line CG00637. 
     Electrophoresis results for CG00637 and the public inbred B37 and W153R are shown in Table 1 below: 
     
                       TABLE 1______________________________________Electrophoresis results for CG00637, B37 and W153RAlleles PresentLocus      CG00637       B37    W153R______________________________________Acp1       2             2      6Adh1       4             4      4Cat3       9             9      9Got1       4             4      4Got2       4             4      4Got3       4             4      4Idh1       4             4      4Idh2       6             6      6Mdh1       6             6      6Mdh2       3.5           6      6Mdh3       16            16     16Mdh4       12            12     12Mdh5       12            12     12Mmm        --            --     --Pgm1       9             9      9Pgm2       8             4      3Pdg1       3.8           2      3.8Pdg2       5             5      5Phi1       4             4      4No. plants 36            24     24______________________________________ 
    
     The data in Table 2 shows the relative hybrid performance of corn inbred line CG00637 crossed to Ciba-Geigy Seed Division (CGSD) corn inbred line CG00567, hereinafter CG00637 ×CG00567, compared to CGSD corn inbred line CG00525 crossed to CGSD corn inbred line CG00567, hereinafter CG00525×CG00567. Corn hybrid CG00525×CG00567 is a proprietary CGSD hybrid currently being sold in the northern United States. The data was averaged across all locations and replications and would include experiments grown by eight CGSD corn research programs in 1989 and 1990. 
     
                       TABLE 2______________________________________Corn hybrid CG00637 × CG00567 compared toCG00525 × CG00567  HYBRID______________________________________                           Har-  Percent  Yield  Percent  Percent  vest  Dropped  (BU/A) Moisture Erect    Roots Ears  No. Locations    142      146      141    44    86______________________________________CG00637 ×    126      24.0     95.9   1.4   0.50CG00567  120      26.3     93.7   1.6   0.33CG00525 ×     6        2.3      2.2   0.2   0.17CG00567Difference______________________________________  Percent  Barren            Percent    Standard  Plants  Intactness                    Green      Index  No. Locations    16        105       5        168______________________________________CG00637 ×    3.4       3.7       29.2     186CG00567  5.2       3.7       43.0     173CG00525 ×    1.8       0         13.8      13CG00567Difference______________________________________ 
    
     The data show that CG00637 has an advantage over CG00525 for maturity (percent moisture), percent erect and percent barren plants. In this and other hybrid combinations, CG00637 has shown outstanding yield performance relative to other commercially sold hybrids of similar maturity 
     At least 2,500 inbred seeds of CG00637 have been placed on deposit at the American Type Culture Collection (ATCC), Rockville, Md., 20852, under deposit accession number 75166 on Nov. 27, 1991. 
     Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the invention, as limited only by the scope of the appended claims.