LIBRO-CONGRESO-CITRUS

lowest levels at fruit mature stage in November, but Ca and Fe contents in fruit showed their lowest levels
in young fruit stage from April to June. (2) N, P, K and Cu contents were significantly higher in fruit pulp
than in fruit peel. Ca, Mn and B contents were significantly lower in fruit pulp than in fruit peel. Mg and S
contents were very close in fruit pulp and peel. Contents of Zn and Fe were significantly higher in pulp than
in peel before September but turned into opposite after September. (3) The main period for accumulation
of N, P, K and Mg in fruit was in June and July. During this period of time in mature fruit, 45.6%, 44.6%,
53.7% and 57.2% of total N, P, K and Mg were accumulated, respectively. The main accumulation period
of micro-nutrient elements in fruit was from June to September. (4) At mature stage, there were about
560mg N or K, 274.9 mg Ca, 42.3-57.3 mg P, Mg or S, and 0.17-3.3mg micro-nutrient elements in each fruit.
S06P05
The effects of source-sink ratio on leaf photosynthetic characteristics of ‘Newhall’ navel orange
Chun C. 1 , Wenwen Z. 2 , Liangzhi P. 3 , Lili L. 1 , Xingzheng F. 1 , Li C. 3 , Xiaohuan M. 2 , Fa X. 2 , Cai L. 2 , and Cailun J. 1
1 Citrus Research Institute, Southwest University, Chongqing (CRIC,SWU,CQ), China; 2 College of Horticulture and Landscape,Southwest
University,Chongqing (CHL,SWU,CQ), China; and 3 National Citrus Engineering Research Center,Chongqing, (NCERC,CQ), China.
chuncpzi@163.com
Leaf growth and photosynthetic characteristics were measured on 30-year-old ‘Newhall’ navel orange
(Citrus sinensis) mature leaves on three types of shoots, including no fruit-bearing shoots (NFS), one fruitbearing
shoots (OFS) and two fruit-bearing shoots (TFS), during fruit development period in 2010. Leaves
of NFS were larger, thicker, higher relative chl and higher nitrogen (N), phosphorus (P), potassium (K)
concentration than the leaves of fruit-bearing shoots (FBS). The net photosynthetic rates (Pn) of leaves on
the top 2nd and 4th nodes on NFS were significantly or very significantly higher than those of the same
position leaves on FBS, as well as the average Pn of the 2nd, 4th and 6th leaves (except for on 150th day
after full bloom). As to the leaf Pn of the two types of FBS, the OFS was slightly higher, and the significant
difference of the average Pn of the 3 position leaves between the two types of FBS occurred on 130th day
after full bloom. With the fruits bearing increased on a shoot, the leaf thickness, leaf area, leaf N level,
leaf P level, leaf K level, relative chl content and average leaf stomatal conductance (Gs) decreased along
with the intercellular CO 2 concentration (Ci) and transpiration rate (E) increasing. For all the 3 types of
shoots, as the position of the leaves on a shoot located lower, the leaf N, P and K level increased. For the
area, thickness, relative chl content and Pn of leaves located on different shoot positions. Fruits from the
OFS were larger with thicker peel, significantly higher Vc content than fruits from the TFS. Therefore, the
relatively poor differentiation and development of leaves on FBS resulted in their lower Pn. Compared with
the leaf differentiation and development, source-sink ratio had slighter effects on leaf Pn.
S06P06
Anatomy of abnormal ‘HB’ pummelo caused by boron deficiency
Li S. 1 , Liu Y.Z. 1 , Yang C.Q. 1 , and Peng S.A. 1
1Key Laboratory of Horticultural Plant Biology (KLHPB), Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, P.
R. China. ganjuli_2002@mail.hzau.edu.cn
Boron (B) deficiency is a worldwide nutritional disorder in citrus industry. Under B deficient condition,
symptoms of corky split veins in mature orange leaves, weak tree vigor and low yield are always visible.
Moreover, B deficiency could reduce fruit size (shrunk fruit) and increase fruit peel thickness. In this study, we
used paraffin section technique to investigate the anatomic structure of mature-fruit albedo between normal
and B deficient fruits, by using ‘HB’ pummelo (Citrus grandis) as research material. As compared with in the
normal fruit, the spongy cells arranged compactly and the average number of vascular bundle per eyeshot
increased in the albedo of B deficient fruit. Moreover, vascular bundles could be found to be linked and the
trachea density or trachea number in vascular bundle was obviously increased in the spongy tissue of the
abnormal fruit. In addition, we also isolated vessel elements from the spongy tissue and compared their
difference between the normal and abnormal (B deficient) fruits. In general, normal vessel elements from
spongy tissue are plump. However in the spongy tissue of B deficient fruits, they deformed with hyperplasia
and uneven vessel wall; moreover, much perforation could be found in the vessel side wall and the number of
pitted vessel increased while the numbers of scalariform and reticulated vessels decreased.
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