بررسي سيستم آوندي در محور سنبله ارقام مختلف گندم

The study of vascular system in different varieties of wheat spike

This experiment was conducted in Educational-Research Agriculture of the Islamic Azad University (IAU), Saveh Branch, in 2007-08 farming year, aimed at the examination of the vascular transfer system in the main rachis of the wheat spike in three types of wheat cultivars including; Atrak, Pishtaz and Veery as a randomized complete blocks design. In this experiment, the internodes of the spike besides the manner of their distribution were examined. Results of this study indicates a significant 1:1 relationship between the spikelets on the rachis and the number of central vascular bundles in the lower part of the rachis. The number of central vascular bundles on the rachis, decreased acropetaly. This decrease regarding the central vascular bundles was averagely 0.5 of vessels in each internode between the internodes 1-4 (the lower part of the rachis), and averagely 1.2 of vessels between 5-14 internodes (central part of the rachis) and from the internode 15 to the terminal (upper part of the rachis) the average was about 0.7 of the central vessel. The size of vascular bundles on the length of the rachis decreased in the form of a special model, in a manner that the highest size of the vascular bundles were related to the central part of the rachis and then in lower and upper parts, respectively. There was also noticed a positive correlation between the number and weight of the grains in relation to the grains and size of the vascular bundles allocated to each spikelet on the length of the rachis, in a manner that the spikelets located in the central part of the spike, accuping the maximum average of weight and number of grains, had the highest number and size of central vascular bundles in this part as compared to other parts of the rachis.