Litchi ( Litchi chinensis Sonn., Sapindaceae) is an important subtropical fruit tree that originated in China. Due to the delicate flavor, pleasant appearance, and fragrance, it has been known as “one of the top four fruits” along with banana
Chunyang Zhang, Jiefang Wu, Danwen Fu, Limin Wang, Jiezhen Chen, Changhe Cai, and Liangxi Ou
F. Zee, K.M. Aradhya, and R.M. Manshardt
A genetic diversity analysis involving 49 Iychee (Litchi chinensis Sonn.) accessions using eight enzyme systems encoding 12 loci (Idh-1, Idh-2, Mdh-2, Per-1, Pgi-2, Pgm-1, Pgm-2, Skdh, Tpi-1, Tpi-2, Ugpp-1, and Ugpp-2) revealed moderate to high levels of genetic variability. Cluster analysis of the isozyme data from 40 genetically different accessions of the total 49 identified three groups at the 50% level of genetic similarity, the largest of which contained 32 of the 40 accessions distributed in three sub-groups. The groups including the three subgroups differed in frequency and composition of alleles at different loci. Polymorphism was observed in 77% of the loci, with an overall mean of 2.2 alleles per locus and an observed heterozygosity of 0.387. The unbiased genetic identities (I) between groups ranged from 0.809 to 0.937. Summing over all 11 polymorphic loci, 16% of gene diversity was due to differentiation between groups and 84% within groups. Comparison of isozyme fingerprints revealed that some accessions with identical names, particularly of `No mai tsz', `Kwai mi', and `Hak ip', possessed different isozyme genotypes, while other accessions with different names displayed identical isozyme genotypes. Isozyme fingerprinting will be useful in revealing and resolving questions of clonal identity, which are common in Iychee germplasm collections.
Yee Kwan Chan, Yung Hua Yang, and Ning Li
Lychee (Litchi chinensis Sonn.) fruit were harvested at green, pink, and red developmental stages. The fruit of each group were used to determine developmentally and environmentally (chilling) regulated ethylene production. The rate of ethylene production in the fruit was green > pink > red. Storage at either 4 or 10 °C increased C2H4 production as much as 8.6-fold compared with control fruit stored at 25 °C. The green fruit were most responsive to chilling in terms of ethylene production.
Jiefang Wu, Danwen Fu, Jiezhen Chen, Changhe Cai, Qian Yan, and Liangxi Ou
Litchi ( Litchi chinensis Sonn.) originated in southern China and northern Vietnam but has now spread to countries with subtropical climates ( Menzel and Waite, 2005 ). Litchi is not only an important fruit in China, India, Vietnam, and Thailand
Hai-Fang Yang, Hye-Ji Kim, Hou-Bin Chen, Jillur Rahman, Xing-Yu Lu, and Bi-Yan Zhou
Litchi ( Litchi chinensis Sonn.) is an evergreen fruit tree widely cultivated in southeast Asia. However, unreliable flowering is a serious problem in the litchi industry. Litchi flowering is induced by low temperatures and enhanced by drought in
Hannes Robbertse, Jaco Fivaz, and Chris Menzel
The architecture of the lychee tree and the structure of the inflorescence are described according to the terminology of Hallè et al. and Weberling. The lychee tree has rhythmic modular growth and the inflorescence is a heterocladic pleiothyrsoid. Additional paracladia may develop from a second serial bud below the first-order paracladia. Male and female flowers are borne at variable positions on the dichasia. The relation between the position and gender of the flowers on the partial inflorescences (dichasia) varied with cultivar and time.
Chemda Degani, Jiusheng Deng, Avigdor Beiles, Ruth El-Batsri, Moshe Goren, and Shmuel Gazit
There is widespread confusion and uncertainty concerning the identity of lychee cultivars: the same cultivar may be known under different names and different cultivars may appear under the same name. In the present study, the potential of intersimple sequence repeat (ISSR) for the identification of 66 lychee cultivars and accessions and a determination of their genetic relationships was evaluated, using 32 primers containing different simple sequence repeat motifs. Of the 194 bands produced, 124 (64%) were polymorphic. A set of six ISSR primers was sufficient to distinguish all cultivars and accessions. Thus, cultivars which are morphologically very similar and have identical isozyme profiles can be distinguished by ISSR analysis. However, seven pairs of accessions, each considered to be the same cultivar, were found to be identical by ISSR analysis. Nei and Li band-sharing distances and Nei genetic distances were calculated among the cultivars and two similarity dendrograms were generated using the neighbor-joining algorithm. Results showed that the ISSR technique is a valuable tool for identification of lychee cultivars and analysis of their genetic relationships.
Thomas E. Marler and Leah E. Willis
`Mauritius' lychee (Litchi chinensis Sonn.) trees were planted in root observation chambers in July 1990 to determine the pattern of root and stem extension growth during 12 months. Root and stem lengths were measured at intervals ranging from 7 to 18 days from Aug. 1990 until Aug. 1991. During each period of active canopy growth, up to six stem tips were tagged and measured. Root growth was determined by measuring tracings of the extension of each root in a visible plane of the glass wall of the observation chambers. Stem growth was cyclic, with distinct periods of rapid extension followed by periods with no extension. In contrast, root growth was fairly continuous with only three periods of no visible root extension. Mean absolute extension rates were higher for stems than for roots. There were no consistent relationships between the timing of root and stem extension growth.
Raphael A. Stern, Daniel Stern, Moshe Harpaz, and Shmuel Gazit
Application of TP as Tipimon® or TPA as Maxim® at the young fruitlet stage significantly increased yield in three lychee (Litchi chinensis Sonn.) cultivars: `Mauritius', `Floridian', and `Kaimana'. Application of TP followed by TPA a week later increased yield more than did either substance alone. In all experiments, TPA increased fruit size and weight, relative to both controls and TP-treated trees. The increased yield did not prevent the increase in fruit size. Use of sprays of TPA may be an effective way of satisfying the market demand for large lychee fruit. Chemical names used: 2,4,5-trichlorophenoxypropionic acid (TP); 3,5,6-trichloro-2-pyridyloxyacetic acid (TPA).
S.J.R. Underhill and C. Critchley
Mature lychee (Litchi chinensis Sonn.) fruit were heat-treated at 60C for 10 min to study heat-induced pericarp browning. Polyphenol oxidase (EC 18.104.22.168) activity of the pericarp increased immediately, corresponding with rapid anthocyanin degradation, Tissue browning was observed 2 min after heating, with pigmentation distributed uniformly throughout the pericarp. The distribution of brown pigments was different than the highly localized browning observed under ambient desiccation. Although both ambient and heat-induced pericarp browning are visually similar, the anatomical distribution of brown pigmentation is quite distinct. The distribution of brown pigmentation was not consistent with anthocyanin localization. Following ambient desiccation, the mesocarp became colorless even though this represented the greatest concentration of pigment. Browning caused by heating may result from nonselective degradation of a range of compounds, including anthocyanin.