Evaluation of genetic variation and correlation of morphological and phenological characteristics and their effects on flower yield of Rosa damascena Mill accessions in Kurdistan

Forty-nine accessions of Damask rose (12 endemic of Kurdistan and 37 from other parts of Iran) were evaluated for genetic variation and correlation of morphological and phonological characteristics and their effects on flower yield using randomized complete blocks design with 3 replications during 2004-8 in Sanandaj (Kurdistan). Recorded data of characteristics in 2006-8 were used for analyses. Significant difference (p.0.01) was observed for nearly all studied traits among accessions and years. The variance of accession- year interaction was significant for phonological and major of morphological characteristics. According to results, leaf bud activation, leaf bud opening, leaf completing, floral bud appearance, flower opening, flowering end, fall beginning and fall occurred in Sanandaj condition at 30 Mar., 23 Apr., 15 May, 14 Jun., 29 Nov. and 14 Dec. respectively and average growing period for accessions was 331 days. Total means (accessions and years) of plant height, crown diameter, leaf number in plant, total green surface, leaf area index, paste (Aphis) contamination percent and plant vigor(range were 1 to 5) was 118.06cm, 192.15 cm, 3284.93, 64237.14 cm2, 1.5, 12.20% and 2.7 respectively. Plant height and crown diameter were significant negatively correlated (p.0.01) with leaf bud opening, leaf completing, floral bud appearance, flower opening,fruit size, seed number per fruit and fall percentage while were significant positively correlated (p.0.01) with leaf number per plant, total green area, leaf area index, flower diameter, petal number per flower, flower number per plant and flower yield. Total mean (accessions and years) of horizontal branches with main stem angle was 42.3O degree, leaflet number per leaf was 6.2, leaflet length was 2.5 cm, leaflet width was 1.8 cm, leaflet size (length* width) 4.6, leaflet length / width ratio 1.4, leaflet area 2.98 cm2, dry weight of leaf 0.22 g, leaf length 5.9 cm, leaf width 4.9 cm, leaf area 18.4 cm2, leaf weight / area ratio 0.1 g/cm2, torn density per 10cm of stem or branch 14.9, flower diameter 5.8 cm, pistil Number 33.5, anther number 57, stipule length 1.09 mm, stipule width 0.41mm, stipule size(length* width) 0.48, stipule length/ width ratio 3.07, floral bud length 1.20 cm, floral bud width 0.8 cm, floral bud size 1.12, floral bud length / width ratio 1.44, torn length 0.5 cm, receptacle length 0.6 cm, receptacle width 0.4 cm, receptacle length * width 0.3, receptacle length / width ratio 1.5, peduncle length 2.4 cm, petiole length 1.6 cm, fruit length 16.3mm, fruit width 11.4mm, fruit length / width ratio 1.6, seed number per fruit was 4.7. Total mean (accessions and years) of flowering period was equal to 29.5 days, flower number per plant 539.14, flower wet weight 2.38 g, flower yield per plant equal to 1205.11g, flower dry weight 1.89 g, flower dry matter percentage 20.37%, petal wet weight 1.85 g, petal number per flower 38.52, petal dry weight 1.58 g, petal / flower weight ratio 0.79, petal yield per plant was equal to 943.13g, essence gain was equal to 0.00011 or 0.01%, essence yield per plant was equal to 0.1313 g. The accessions of Fars1, Kurdistan2, Kurdistan3, Fars2, Ardabil1 and Yazd2 with flower yield per plant equal to 2963, 2274, 2069, 2016, 1870 and 1870g respectively produced the highest flower yield while Lorestan1 with 225 g produced the lowest flower yield. The accessions of Isfahan3, Isfahan2, Kurdistan2, Isfahan4 and Fars 2 with essence yield per plant equal to 0.3719, 0.3403, 0.3279, 0.2838 and 2665g produced the highest essence yield. The comparison of means of years suggesting that dry years (such as 2006 and 2008) or drought conditions decreases flower yield and yield components as well as most of other morphological traits. The drought condition resulted in earlier performance of phonological traits. Flower yield per plant showed significant negative correlation (p.0.01) with days to leaf bud opening, leaf completing, floral bud appearance, flower opening and petal number per plant, seed number per fruit and fall percentage while significant positive correlation (p.0.01) with plant height, crown diameter, leaf 99 number in plant, total green surface, leaf area index, flower number per plant, petal yield per plant, essence yield per plant, horizontal branches with main stem angle, leaflet size (length* width), leaflet area, dry weight of leaf, leaf area, flower diameter, receptacle length * width, petiole length and growing period. The results of stepwise regression showed that petal yield per plant, petal / flower weight ratio, essence gain, leaflet size, days to leaf bud activation, peduncle length, leaflet area, flower diameter, torn length, plant age and leaf width with determination coefficient equal to 98.55% described major flower yield changes. The results of stepwise regression showed that essence gain, flower yield per plant, leaf area index, stipule width, leaf length, days to flower opening, peduncle length, plant age, fall percentage and leaf weight / area ratio with determination coefficient equal to 92.93% described major essence yield changes. According to results, the higher flower and essence yield needs to the higher vegetative growth and vigorous plants as well as earlier performance of phonological traits and longer growing period. The results of cluster analysis absed on the standardized data of all studied traits classified accessions in 6 distinct groups. It also revealed that a number of accessions such as Fars1, Kurdistan3, Kurdistan7 and Kurdistan12 were classified in separated groups due to those characteristics.