1.

Fingerprinting and Genetic Similarity of Chinese Cabbage (Brassica rapa Pekinensis Group) Inbred Lines Based on AFLP Markers

Kou-Chang Hsu ¹⁾ and Woo-Nang Chang ²⁾

1) Graduate student in Ph D. Program, and ²⁾ Professor, Department of Horticulture, National Chung-Hsing University, Taichung, Taiwain 40227

Amplified restriction fragment length polymor-phism (AFLP) was used to determine the genetic similarity and relationship among 23 inbred lines of Chinese cabbage (Brassica rapa Pekinensis Group). Using only six pairs of primer combination, 381 AFLP bands were detected of which 280 were polymorphic. An average of 46.6 polymorphic bands was found with each pair of primer. These polymorphic bands can be used as fingerprints for testing inbred lines. Cluster analysis using AFLPs data, could revealed the relatively genetic similarity and relationship between the tested lines. The results show that a large number of molecular markers obtained by AFLPs provides detailed genetic information, which may improve the breeding efficiency.

Key words: AFLP, molecular markers, polymorphism, Brassica rapa Pekinensis Group, diversity.

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2.

Application of Random Amplified Polymorphic DNA (RAPD) Markers on Cultivar Identification of Capsicum annuum L.

Cheng-Chieh Lin¹⁾, Woo-Nang Chang²⁾ , and Yu Sung³⁾

1) Graduate Student, ²⁾ Professor and ³⁾ Associate professor, of the Department of Horticulture, National Chung Hsing University.

Ten DNA primers selected from 110 random DNA primers were applied to 7 pepper (Capsicum annuum L.) cultivars from Know-You Seed Company. The results showed polymorphic patterns. Forty-nine pepper cultivars from Know-You and Evergrow seed companies were subjected to RAPD analysis. The ten selected primers produced a total of 115 bands, of which 84 were polymorphic, with more than 70% polymorphism among the 49 cultivars. The least similarity of cluster analysis was 81.3%. Dendrogram demonstrated that sweet pepper and hot pepper could be distinguished by cluster analysis using RAPD markers, with the exception of the cultivars ‘Peace Star’ and ‘Group Star’. Sweet cultivars ‘Uranus’ and ‘Big Star’, both from Know-You Seed Company, showed a least similarity of 96.2%. Know-You sweet cultivars ‘Vega’ and ‘Beauty Bell’ and Evergrow sweet cultivars ‘Square Lamuyo’, ‘Rich Square’, and ‘Blocky Red’ were in the same group and had a least similarity of 96.7%. The morphological variation of peppers can be clearly related to the variation detected by RAPD polymorphism. Cluster analysis of RAPD markers provided a reliable way to identify the genetic relationships among pepper cultivars.

Key Word：Random Amplified Polymorphic DNA (RAPD) Markers, Cultivar Identification, Capsicum annuum L.

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3.

Virus Re-infection of Specific-viruses-free Micro-propagated Grapevine Seedlings in the Field

Tso-Chi Yang, Yu-Ju Liao, and Tzay-Fa Sheen

Taiwan Seed Improvement and Propagation Station, Taichung Pref., Taiwan

Grapevine is one of the most widely planted fruit crops in Taiwan, covering an area of approximately 3110 hectares. Vegetative cutting is the major means for grapevine propagation. However, it also provides the transmission pathway of several important viruses throughout the world. To improve the fruit quality and quantity reduced deteriorously by virus infection year by year, specific-viruses-free grapevine seedlings were propagated using in vitro technique in Taiwan Seed Improvement and Propagation Station. The major objective in this study was to evaluate the virus re-infection of these healthy planting materials in the fields when they were used as a strategy for grapevine viral disease control. The results revealed that the re-infection percentage of grapevine A trichovirus (GVA) reached 17.5%, 34.5%, and 27.5% in Nantou, Changhwa, and Taichung counties in 1999, respectively. The re-infection percentage of grapevine fanleaf nepovirus (GFLV) reached 78.2%, 85%, and 20 % in Changhwa, Taichung, and Miaoli counties, respectively. However, grapevine leafroll closterovirus-strain 1 (GLRaV1) only occurred in Taichung County with 5 % re-infection in 1999. In addition to serological results, the crystalline inclusion bodies induced by GFLV and irregular inclusion bodies in phloem tissue induced by GVA or GLRaV1 could also help identifying the incidence of the above three viruses in Taiwan.

Key words: Grapevine、Specific-viruses-free seedlings、virus re-infection

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4.

Philosophy behind the Disagreement in the Usage of S.D. and S.E.

Yih-Chang OU¹⁾, Dah-Jing Liaw²⁾, Juinn-Lung LIN³⁾ and Yun-Ming PONG⁴⁾

¹⁾Department of Agronomy, National Taiwan University
²⁾Graduate Institute of Statistics, National Tsing Hua University
³⁾Department of Agronomy, National Chung-Hsing University
⁴⁾Department of Agronomy, National Taiwan University

According to the definition introduced by K. Pearson (1893; cf. Kendall and Buckland, 1982), standard deviation (SD) is the positive square root of the variance of a frequency distribution. For some reasons, statisticians prefer to use the term standard error (SE) instead. In our survey, we find that the usage of the term SE may be classified into two categories:
(1) Both SD, such as s/(n)^0.5, and estimated SD, such as s/(n)^0.5, of a statistic are referred as the SE of that statistic, such as ^Y.
(2) Only estimated SD, such as s/(n)^0.5 of a statistic is referred as the SE of that statistic, such as ^Y.

The philosophy for calling  s/(n)^0.5 standard `error' is that  s/(n)^0.5 is viewed as a measure of the estimation error |^Y-m|. For this reason,  s/(n)^0.5 is also a measure of estimation error |^Y-m|. On the other hand, the philosophy for calling  s/(n)^0.5 SD and calling s/(n)^0.5 SE implies that an error occurs on the substitution of s for s. This study found that majority of statisticians opted for the first usage. Although there is no established correct usage of the term SE, we still recommand research workers and students to stick to the first usage. Otherwise, confusion about the usage of these two terms might be incurred.

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5.

Genetic identification of Oncidium accessions by molecular markers

Fure-Chyi Chen^1*), Wan-Ling Wu²⁾, Chun-Hua Pan³⁾, Irwin Yau-Yuan Chu⁴⁾ and Yau-Wen Yang⁵⁾

1)Professor and ²⁾Research assistant of Department of Plant Industry, National Pingtung University of Science and Technology, Pingtung, Taiwan
³⁾Research specialist and ⁴⁾General manager of Taiwan Flower Biotechnology Co., Taipei
⁵⁾Associate research fellow of Institute of Botany, Academia Sinica, Taipei
^*Corresponding author, e-mail: furechen@mail.npust.edu.tw

Molecular markers by random amplified polymorphic DNAs were used to evaluate the genetic variation among different Oncidium accessions. We were able to distinguish different registered Oncidium hybrids, including Gower Ramsey, Sweet Sugar and Taka using 9 random primers. Furthermore, variation was also detected within different cultivars that derived from same hybrids. For example, several cultivars of Gower Ramsey clone derivation could be distinguished based on molecular markers. Based on dendrogram, the investigated cultivars were clustered into several groups. Onc. Gower Ramsey and its selected clone derivation cultivars were in one group. Onc. Sweet Sugar, Onc. Taka and Onc. Sharry Baby ‘Sweet Fragrance’ were clustered in separate groups. The usefulness of molecular markers in genetic identification of Oncidium orchids was also discussed.

Key words: Oncidium spp, genetic variation, random amplified polymorphic DNA (RAPD)

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