A plant breeder at the U.S. Regional Pasture Research 
Laboratory, University Park, Pa., examines white clover 
introductions. 
—Available genetic, cytogenetic, and pathological 
information does not provide adequate guidelines for 
breeding. 
To improve methods of breeding grasses and leg- 
umes, we need more information on— 
@ Isolating sources of superior lines of plant 
material. 
® Improving techniques for emasculation, pollina- 
tion, and selfing. 
® Clarifying pollination patterns within isolated 
breeding nurseries. 
®@ Developing efficient testing procedures for field 
studies. 
® Comparing contrasting selection procedures. 
® Developing techniques for studying parent- 
progeny relationships. 
® Developing systems for combining lines into 
varieties. 
@ Finding systems for maintaining genetic stability 
of varieties. 
® Developing multiplication procedures for new 
varieties and hybrids. 
e 
eS 
70 
There are 15 chromosomes (seven pairs and a single 
chromosome) in this plant derived from tetraploid 
BN—29499 
crested wheatgrass (2n=28 chromosomes) at Logan, 
Utah. Chromosome studies provide a guide to the 
origin of species and to inheritance patterns. 
BN—29510 
These plants from twin seedlings have different numbers 
of chromosomes. 
oF 
