CORNELL UNIVERSITY
Department of Plant Breeding and Biometry, Ithaca, NY 14853-1901,
USA.
M.E. Sorrells.
1995 winter wheat production.
The 1995 soft white winter wheat crop for New York
was 125,000 acres, slightly below average for the state. Yield
was estimated to be 55 b/acre, the second highest average yield
on record. For 1995, temperatures were near normal, but precipitation
was 13 cm below normal for April through July. Precipitation
was well below normal for every month.
Batavia, Harus, Geneva, and Pioneer Brand 2737W are
soft white winter cultivars currently recommended to New York
farmers. Limited quantities of certified seed of Cayuga (NY262-37-422)
were available this past fall. Geneva Reselect (reselection of
Geneva) has been approved for release. This line has shown exceptionally
high yield for the past 4 years. Although it was found in a Foundation
seed field of Geneva, it is much shorter and has white instead
of bronze chaff.
Soft red cultivars that are performing well in New
York state trials include Hoffman 89 and Pioneer Brands 2548,
2545, and 2510. The soft red winter market class continues to
gain in popularity, especially following years when considerable
damage was caused by preharvest sprouting in the white wheats.
We tested our soft red entries for sprout resistance this past
year for the first time. Those entries showing above-average
sprouting damage were Cardinal, CL860434, C4227, and Casey. Also,
Presto triticale showed more damage than most reds. Spelt varieties
ranged from very resistant to very susceptible. We have initiated
a fee testing program for private varieties. The trials are grown
in four locations, and the fee is $200 per entry.
Production of hard red spring wheat continues at
a low level. Stoa continues to be the most popular variety.
Our research program currently is focussed on comparative
mapping. We developed consensus maps for members of the Triticeae
tribe (T. aestivum, T. tauschii, and Hordeum
spp.) and compared them to maps for rice, maize, and oat. The
aneuploid stocks in wheat have been invaluable to comparative
mapping, because almost every DNA fragment can be allocated to
a chromosome arm, thus preventing erroneous conclusions about
probes that could not be mapped because of the lack of polymorphism
between mapping parents. The orders of markers detected by probes
mapped in rice, maize, and oat were conserved for 93, 92, and
94 % of the length of Triticeae consensus maps, respectively.
The duplicated chromosome segments within the maize genome, because
of ancient polyploidization, were identified by homoeology of
segments from two maize chromosomes to regions of one Triticeae
chromosome. Homoeologous segments conserved across Triticeae species,
rice, maize, and oat were identified for each Triticeae chromosome.
We have identified a set of cDNA probes to map as
anchor loci across rice, wheat, oat, and maize. These probes
hybridized across several grass genera and demonstrated their
efficacy for comparative mapping. The anchor probes were used
to extend the existing RFLP linkage maps of rice, maize, wheat,
oat, sorghum, and sugarcane and to compare map structure between
these crops. Comparisons based on the map position of anchor
probes demonstrated the collinearity of cDNA markers across the
genera and revealed conserved rearrangements and duplications.
Correspondence of QTL with qualitative genes in homoeologous
chromosome segments of other species indicate that the genes underlying
many of these traits may be orthologous.
Wheat spindle streak mosaic virus resistance.
In collaboration with Dr. G. Bergstrom, we developed
a recombinant inbred population from the cross `Geneva/Augusta'
for the purpose of mapping resistance to WSSMV. We have completed
3 years of evaluation of visual symptoms of this virus, and it
appears to segregate as a single gene. RFLP mapping has been
initiated.
We have completed evaluation of the `Clark's
Cream/NY6432-18' mapping population for milling and baking
quality traits with the goal of mapping those genes. We have
identified genes controlling flour protein concentration, alkaline
water retention capacity, and flour yield. We also are analyzing
mixing strength. This is a colloborative project with the Wooster
Soft Wheat Quality Lab, Jim Anderson, and Kim Campbell.
Publications.
Autrique E, Nachit MM, Monneveux P, Tanksley SD,
and Sorrells ME. 1996. Genetic diversity in durum wheat based
on RFLPs, morphophysiological traits and coefficient of parentage.
Crop Sci 36:735-742.
Autrique E, Singh RP, Tanksley SD, and Sorrells ME.
1995. Molecular markers for four leaf rust resistance genes
introgressed into wheat from wild relatives. Genome 38:75-83.
da Silva J and Sorrells ME. 1996. Linkage analysis
in polyploids using molecular markers. In: Methods of
Genome Analysis in Plants: Their Merits and Pitfalls (Jauhar
P ed). CRC Press, Inc., Boca Raton, FL.
Ma AQ, Zhao Y-H, and Sorrells ME. 1995. Inheritance
and chromosomal location of a male fertility restoring gene transferred
from Aegilops umbellulata Zhuk. to Triticum
aestivum L. Mol Gen Genet 247:351-357.
Ma ZQ, Roder MS, and Sorrells ME. 1996. Frequencies,
and sequence characteristics of microsatellites in wheat. Genome
(In press).
Ma ZQ and Sorrells ME. 1995. Genetic analysis of
fertility restoration in wheat using restriction fragment length
polymorphism. Crop Sci 35:1137-1143.
Nelson JC, Van Deynze AE, Autrique E, Sorrells ME,
Lu YH, Merlino M, Atkinson M, and Leroy P. 1995. Molecular mapping
of wheat. Homoeologous group 2. Genome 38:517-524.
Nelson JC, Van Deynze AE, Autrique E, Sorrells ME,
Lu YH, Negre S, Bernard M, and Leroy P. 1995. Molecular mapping
of wheat. Homoeologous group 3. Genome 38:525-533.
Nelson JC, Sorrells ME, Van Deynze AE, Lu YH, Atkinson
M, Bernard M, Leroy P, Faris JD, and Anderson JA. 1995. Molecular
mapping of wheat. Homoeologous groups 4, 5, and 7. Genetics
141:721-731.
Roder MS, Plaschke J, Konig SU, Boner A, Sorrells
ME, Tanksley SD, and Ganal MW. 1995. Abundance, variability,
and chromosomal location of microsatellites in wheat. Mol Gen
Genet 246:327-333.
Sorrells ME, Van Deynze A, Nelson JC, and McCouch
SR. 1995. Comparative mapping in the Gramineae. In:
Classical and Molecular Cytogenetic Analysis. Proc US-Japan NSF
Symp (Raupp WJ and Gill BS eds). Department Report, Dept. Plant
Pathology, Kansas State Univ. Manhattan Pp. 76-84.
Sorrells ME and Anderson JA. 1996. Quantitative
trait loci associated with preharvest sprouting in white wheat.
In: Seventh Inter Symp on Preharvest Sprouting in Cereals,
July 2-7, 1995, Abashiri, Japan.
Van Deynze AE, Dubcovsky J, Gill KS, Nelson JC, Sorrells
ME, Dvorak J, Gill BS, Lagudah ES, McCouch SR, and Appels R.
1995. Molecular-genetic maps for group 1 chromosomes of Triticeae
species and their relation to chromosomes in rice and oat. Genome
38:45-59.
Van Deynze AE, Nelson JC, Yglesias ES, Harrington
SE, Braga DP, McCouch SR, and Sorrells ME. 1995. Comparative
mapping in grasses. Wheat relationships. Mol Gen Genet 248:744-754.
Van Deynze AE, Nelson JC, O'Donoughue LS, Ahn SN, Siripoonwiwat W, Harrington SE, Yglesias ES, Braga DP, McCouch SR, and Sorrells ME. 1995. Comparative mapping in qrasses. Oat relationships. Mol Gen Genet 249:349-356.