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=6

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=<p>To investigate photosynthetic characteristics of the subtending leaf at the 2–3rd and 10–11th fruiting branch (FBN, FB<sub>2–3</sub>, and FB<sub>10–11</sub>), 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, <italic>Pn</italic> and non-photochemical quenching (NPQ) in the subtending leaf significantly declined, while soluble sugar, amino acid and their ratio (<italic>C</italic><sub>SS</sub>/<italic>C</italic><sub>AA</sub>) as well as <italic>F</italic><sub>v</sub>/<italic>F</italic><sub>m</sub> increased. These results indicated that (1) non-radiative dissipation of excess light energy at FB<sub>2–3</sub> was reduced to improve solar energy utilization efficiency to compensate for lower <italic>Pn</italic>, (2) higher NPQ at FB<sub>10−11</sub> played a role in leaf photo-damage avoidance, (3) boll weight was related to the <italic>C</italic><sub>SS</sub>/<italic>C</italic><sub>AA</sub> 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 <italic>Pn</italic>, sucrose content and <italic>C</italic><sub><italic>SS</italic></sub>/<italic>C</italic><sub><italic>AA</italic></sub> in the subtending leaf at FB<sub>2–3</sub> resulted in lower boll weight and fiber strength.</p>