Correlation between Soybean Leaves and Formation of Flower and Pod Numbers

Three semi-determinate soybean varieties with different maturity,Ken18(early mature),Heinong41(middle mature) and Jiyu60(late mature),were taken as materials to study the relationships between leaf area and flower as well as pod vertical distribution in each node on the main stem,and the influence of removing leaves on the flowers and pods were also investigated.The results showed that,except for the top node,the leaf area,flower and pod numbers all showed an increase and then decease trend from bottom to top on the main stem.Flower and pod formation on top node exhibited obvious apical dominance,while that of penultimate node showed significant disadvantage.After removing the newly grown leaf,the flower and pod numbers on the corresponding node significantly decreased,while the pod formation rate increased remarkably for the three soybean variety.Removing the fully expanded leaf on the 5th and 7th node showed greatest affection on the flower and pod number on the 7th and 9th node,respectively for Ken18;while that had obvious effect on flower and pod number on the 8th and 10th node,respectively for Heinong41 and Jiyu60.Removing the newly expanded leaf could significantly reduce pod number and pod formation rate on the corresponding node.In addition,the elongation and cease of leaves' development were earlier than pods in middle section of soybean main stem,and the interval was significantly extended when the growth period of the varieties increased.Pod number on each node in the middle section were restricted by photosynthesis supply of adjacent node's leaves,and photosynthesis supply of leaves on each node also affected pod number of adjacent node.It was important to increase individual pod numbers by coordinating the interrelation between leaves,flowers and pods on each node of soybean.