Boron deficiency inhibits petiole and peduncle cell development and reduces growth of cotton.

摘要

The growth, and petiole and floral peduncle anatomy of cotton (Gossypium hirsutum cv. Delta Opal) grown in a nutrient solution containing 0, 1.5, 3.0, 4.5 or 6.0 micro mol B litre-1 from 22 to 36 days after plant emergence (DAPE). From 36 to 51 DAPE, B was removed from the nutrient solution. Petioles from young leaves and floral bud peduncles (first position of the first sympodial) were sampled, and the cross-section anatomy was observed under an optical microscope. The number of vascular bundles of the petiole was reduced in B-deficient plants and the xylem was disorganized. Phloem elements in the peduncle vascular cylinder of B-deficient plants did not show clear differentiation. The few xylem elements that were formed were also disorganized. Modifications caused by B deficiency may have impaired B and photosynthate translocation into new cotton growth. B accumulation in the shoot of B-deficient plants suggested B translocation within the plant. Cotton growth may have been impaired by the decrease in carbohydrate translocation rather than by B deficiency in the tissue alone..