AUTHOR=Liu Jingran , meng Yali , Lv Fengjuan , Chen Ji , Ma Yina , Wang Youhua , Chen Binglin , Zhang Lei , Zhou Zhiguo TITLE=Photosynthetic characteristics of the subtending leaf of cotton boll at different fruiting branch nodes and their relationships with lint yield and fiber quality JOURNAL=Frontiers in Plant Science VOLUME=Volume 6 - 2015 YEAR=2015 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2015.00747 DOI=10.3389/fpls.2015.00747 ISSN=1664-462X ABSTRACT=To investigate photosynthetic characteristics of the subtending leaf at the 2-3rd and 10-11th fruiting branch (FBN, FB2-3 and FB10-11), and their relationship with cotton yield and quality, field experiments were conducted using two cotton cultivars, Kemian 1 and Sumian 15. The results showed that with FBN increasing, chlorophyll (Chl) components, Pn and non-photochemical quenching (NPQ) in the subtending leaf significantly declined, while soluble sugar, amino acid and their ratio (CSS/CAA) as well as Fv/Fm increased. These results indicated that 1) non-radiative dissipation of excess light energy at FB2-3 was reduced to improve solar energy utilization efficiency to compensate for lower Pn, 2) higher NPQ at FB10-11 played a role in leaf photo-damage avoidance, 3) boll weight was related to the CSS/CAA ratio rather than carbohydrates content alone, 4) with FBN increasing, lint biomass and lint/seed ratio increased significantly, but lint yield decreased due to lower relative amount of bolls, and 5) the decreases in Pn, sucrose content and CSS/CAA in the subtending leaf at FB2-3 resulted in lower boll weight and fiber strength.