主题：【合作】玉米种子 PH4CV专利翻译合作 -- 急风劲草

发明的详细描述（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, substantially homozygous and reproducible to be useful as parents of commercial hybrids. There are many analytical methods available to determine the homozygotic stability and the identity of these inbred lines.

The oldest and most traditional method of analysis is the observation of phenotypic traits. The data is usually collected in field experiments over the life of the maize plants to be examined. Phenotypic characteristics most often observed are for traits 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. A plant's genotype can be used to identify plants of the same variety or a related variety. For example, the genotype can be used to determine the pedigree of a plant. There are many laboratory-based techniques available for the analysis, comparison and characterization of plant genotype; among these are Isozyme Electrophoresis, Restriction Fragment Length Polymorphisms (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), Simple Sequence Repeats (SSRs) which are also referred to as Microsatellites, and Single Nucleotide Polymorphisms (SNPs).

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, have been widely used to determine genetic composition. Isozyme Electrophoresis has a relatively low number of available markers and a low number of allelic variants among maize inbreds. RFLPs allow more discrimination because they have a higher degree of allelic variation in maize and a larger number of markers can be found. Both of these methods have been eclipsed by SSRs as discussed in Smith et al., “An evaluation of the utility of SSR loci as molecular markers in maize ( Zea mays L.): comparisons with data from RFLPs and pedigree”, Theoretical and Applied Genetics (1997) vol. 95 at 163-173 and by Pejic et al., “Comparative analysis of genetic similarity among maize inbreds detected by RFLPs, RAPDs, SSRs, and AFLPs,” Theoretical and Applied Genetics (1998) at 1248-1255 incorporated herein by reference. SSR technology is more efficient and practical to use than RFLPs; more marker loci can be routinely used and more alleles per marker locus can be found using SSRs in comparison to RFLPs. Single Nucleotide Polymorphisms may also be used to identify the unique genetic composition of the invention and progeny lines retaining that unique genetic composition. Various molecular marker techniques may be used in combination to enhance overall resolution.

Maize DNA molecular marker linkage maps have been rapidly constructed and widely implemented in genetic studies. One such study is described in Boppenmaier, et al., “Comparisons among strains of inbreds for RFLPs”, Maize Genetics Cooperative Newsletter, 65:1991, pg. 90, is incorporated herein by reference.

Inbred maize line PH4CV is a yellow, dent maize inbred that is well suited to be used as either the female or male in production of the first generation F1 maize hybrids. Inbred maize line PH4CV is best adapted to the Central Corn Belt, Eastern, Southcentral, and Southeast areas of the United States and can be used to produce hybrids with approximately a 113 maturity based on the Comparative Relative Maturity Rating System for harvest moisture of grain. Inbred maize line PH4CV demonstrates good female yield and good Southern Corn Leaf Blight, Stewarts Bacterial Leaf Blight and Gray Leaf Spot tolerance as an inbred per se. Inbred maize line PH4CV also has above average tolerance to Diplodia, Fusarium , and Gibberella ear rots as an inbred per se. In hybrid combination, inbred PH4CV demonstrates high grain yield, good foliar disease tolerance, and short ear and plant height.

The inbred has shown uniformity and stability within the limits of environmental influence for all the traits as described in the Variety Description Information (Table 1) that follows. The inbred has been self-pollinated and ear-rowed a sufficient number of generations with careful attention paid to uniformity of plant type to ensure the homozygosity and phenotypic stability necessary to use in commercial production. The line has been increased both by hand and in isolated fields with continued observation for uniformity. No variant traits have been observed or are expected in PH4CV.

Inbred maize line PH4CV, being substantially homozygous, can be reproduced by planting seeds of the line, growing the resulting maize plants under self-pollinating or sib-pollinating conditions with adequate isolation, and harvesting the resulting seed using techniques familiar to the agricultural arts.