To determine the relationship between genetic variation and climatic and geographical classification, 500 bread wheat lines belonging to Iranian Cereal Collections were studied in an augmented design with four checks and 20 blocks, in 1994. Measuerments were made on days to flowering, days to physiological maturity, grian filling period, flag leaf breadth, flag leaf area, length of flag leaf sheath, extrusion length, .peduncle diameter, spike length, plant height, grain yield, biological yield, harvest index, kernel per spike, 1000 kernel weight, spikelets per spike, fertile spikelets, florets per spikelet, fertile florets per spikelet and spikes per plot. The importance of all triats for dissociation of zones and climates was revealed by analysis of variance and preliminary studies of differences among samples for mentioned triats, but the final grouping was made using the characters that had significant correlations with climate grouping index. The cluster and principal component analysis were used for grouping climates and geographical zones of investigated samples. The results showed that there is a good relative relationship between genetic diversity and climatic diversity, while no relationship was found between genetic diversity and geographical classificatin. This study also indicated that the principal component analysis is a useful tool for grouping the evaluated samples of climates.
)