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• Evaluation on Drought Tolerance of Rice Lines with Indica Genetic Background Carrying Chromosome Segment Substitution from Wild Rice (Oryza rufipogon)or Japonica

  Pham Van Cuong, Doan Cong Dien, Tran Anh Tuan, Tang Thi Hanh

  Date Received: 21-10-2014 / Date Accepted: 10-03-2015

   Abstract PDF (VIETNAMESE)

  Twenty chromosome segment substitution lines (CSSLs) developed from IR24 background (5 lines of Ruf ILs (IR24 × O. rufipogon), 15 lines of IAS (IR24 × Assominori - a Japonica cultivated rice) and IR24 were evaluated for drought tolerance at tillering stage. The 3-leaf seedlings were grown in Kimura B + 20% PEG6000 solution (drought treatment) or in Kimura B solution (non-drought treatment). The results showed that, the drought resistance index (DRI) correlated with the dry matter under drought and non-drought conditions with r = 0,614 and r = 0,604, respectively. The number of leaves, leaf area, root surface area, number of roots and root hairs in both CSSLs and IR24 were reduced in drought condition. But, there was no reduction in root numbers and root hairs numbers in CSSLs, which had higher DRI. The results also showed that, drought tolerance mechanism of IAS lines might involve the increase of root growth, water uptake and root-to-shoot water transport. However, the mechanism in Ruf ILs lines might involve the reduction of leaf number, leaf area and in company with increase of root growth and water uptake. These finding suggested that wild rice O. rufipogon and Asominori would be ideal materials for rice breeding for drought tolerance.

• Morphology and Anatomy Characteristics of Rice Line DCG66 Harboring Chromosome Segment from Japonica Asominori in Indica IR24 Genetic Background

  Nguyen Hong Hanh, Nguyen Van Hoan, Pham Van Cuong

  Date Received: 18-01-2017 / Date Accepted: 13-03-2017

   Abstract PDF (VIETNAMESE)

  A pot-experiment was conducted using completely randomized design (CRD) with 5 replications in green house at Faculty of Agronomy, Vietnam National University of Agriculture in autumn season 2016 to evaluate morphological and anatomical characteristics of DCG66 line that caries a chromosome segment substitution from cv. Asominori. Experiment used four entries: cv. Asominori (Subsp. Japonica), cv. IR24 variety (subsp. Indica), IAS66 line - a chromosome segment substitution line (CSSL) derived from IR24 and Asominori cross at BC2F3 generation, and DCG66 line - chromosome segment substitution line seleclted from IAS66 at BC2F8 generation. At heading stage, 5 plants per entry were randomly selected to measure morphological and anatomical characteristics of root, basal internode, panicle internode and flag leaf. At maturing stage, 5 plants/replication were selected to measure yield components and individual yield. The results showed that DCG66 outyielded by 11.5% compared to IR24, 53.5% to Asominori and 29.1% to IAS66 because of large spikelet/panicle. The stem internode diameter, root volume, total of root surface area, number of flag leaf vascular bundles were higher in DCG66 than other entries. There was a positive correlation between number of vascular bundles in panicle and yield components and individual yield at all of research varieties.