Study on Spikelet Distribution Pattern of the Sodium Azide-Induced Mutants of Rice Variety Tainung 67

本研究以自水稻台農67號疊氮化鈉突變庫篩選所獲得的5個穎花分佈型態之突變品系為材料，以誘變親台農67號為對照品種，進行連續2年4期作之穎花分佈調查。結果發現，無論一次枝梗數、一次枝梗穎花數、二次枝梗數及二次枝梗穎花數之數量等性狀，突變品系均產生不同於誘變親台農67號之穎花分佈型式。一次枝梗數增加或減少最多可達3個；大部分突變品系之一次枝梗穎花數均與台農67號相似，約為5~6粒，但突變品系SA0418部分枝梗可增加至7粒。整體而言，每個突變品系在第一期作（2個年度）之二次枝梗穎花數變化曲線並無明顯變異，但第二期作之穎花分佈明顯異於一期作，且年度間表現不一致。突變品系SA04018之二次枝梗穎花數明顯減少，2001年2期作甚至減少到二次枝梗幾乎無穎花之生產，台農67號之二次枝梗穎花數以中部節位最具優勢，突變品系SA04019於一期作則以中上部節位最具優勢，對穗之乾重累積特性而言，可能為優良之突變性狀。總而言之、水稻穎花分佈會隨年度、期作及誘變處理而改變，疊氫化鈉誘變處理可增加穎花分佈之變異程度及產生優良穎花分佈型態之品系，值得研究利用。 Five mutants derived from sodium aside mutagenesis with various spikelet distribution patterns on rice panicle were investigated and compared with its mother parent, TNG67 variety, for four crop seasons. The results have shown that the significant differences were observed in primary rachis-branches number, spikelet number on the primary rachis-branch, number of the secondary rachis-branch and number of spikelet on the secondary rachis-branch as compared with the characteristics of TNG67 variety. Most mutants and TNG67 produce 5~6 spikelets on the primary rachis-branch, but mutant SA0418 produced 7 spikelets on parts of its primary rachis-branch. No distinct difference in spikelet distribution on secondary rachis-branch was observed in the first crop season for two years but it was not stable in the second crop season. Mutant SA0418 produced less spikelets in the secondary rachis-branch as compared with TNG67, and most spikelets were found in the secondary rachis-branch, especially in the secondary crop season of year 2001. In mutant, SA0419, a large number of spikelets distributed in the secondary rachis-branch above the middle nodal in the first crop season providing a good characteristic for dry matter accumulation in rice panicle. In conclusion, spikelets distribution pattern of rice may have variable expressions in different year and crop season, and can also be altered by mutagenesis. Rice mutants with variations in spikelet distribution pattern provide good characteristics for further physiological study as well as variety improvement

Screening of Rice Mutants from a Sodium Azide Derived Mutation Pool of Tainung 67 Variety: Grain Appearance and Amylose Mutants

本試驗以疊氮化鈉誘變所建立之台農67號突變庫已純化之1，120個M7世代突變品系為材料，進行米粒外觀及直鏈性澱粉含量突變體之篩選，結果發現突變品系之白米率及完整米率之突變範圍分別為44~81%及0~78%。突變親台農67號之穀粒外穎及種皮為無色，米粒呈透明，透明度中等，部份米粒有腹白，極少數有心白發生。經誘變後發現有完全心白、完全腹白及不同程度之乳白粒突變體出現，部分品系透明度增加，呈晶瑩剔透狀，但也有很多品系變成似糯性之不透明色。突變後米粒直鏈性澱粉含量分佈範圍從糯性至31%，變異範圍明顯廣大，且呈連續分布。而具有相同直鏈性澱粉含量之突變品系其農藝性狀、千粒重、結實率及米粒型態也呈現相當大之變異。利用糙米橫切面碘液染色，可快速分辨糥性與非糯性突變體、乳白米與糯米突變體，然而所分離的糥性突變品系間，仍有部分直鏈性澱粉合成之差異存在。總之，疊氮化鈉誘變劑誘導水稻台農67號產生許多碾米品質、米粒外觀及直鏈性澱粉含量差異之突變體，提供同一米質多樣性變異之資源，可直接評估其利用性或作為探討澱粉合成之機制及影響米質之相關生理生化特性之材料，提供改進米質與產量之參考。 In this paper, we report the screening of grain appearance and amylose content from 1,120 mutants in M7 generation of a mutation pool derived from TNG67 rice variety induced by sodium azide mutagenesis. The results show that the range of variations in milled rice rate and head rice rate are 44-81% and 0-78%, respectively. The grains of TNG67 variety show colorless husk and seed coat, middle translucent and partial white-belly, mutants colored husks and seed coats, high translucent, all white-belly, milk-white and transparent grains are observed. The grain amylose content of mutants shows continuous distribution to 31%. Mutants with similar amylose content possess various grain characteristics in 1000-grain weight, grain filling rate and morphological shape. Grain cross-section staining with iodide could be applied to differentiate the waxy mutant from non-waxy, milk-white, and waxy-pigmented mutants. These grain mutants provide good materials for rice food processing and starch metabolism studies, and germplasms for rice variety and quality improvement

(57(1):33-48)Studies on Anthocyanidin and Total Phenolic Contents of Sweet Potato

甘藷 (Ipomea batatas) 之不同品種具有豐富之色彩，其花青素組成份及抗氧化能力 值得開發研究。試驗結果得知紫紅色系之藷皮及藷肉均有花青素之合成，花青素之種類 有紫紅色的矢車菊素 (cyanidin) 及紅色的芍藥素 (peonidin)，顏色愈深花青素含量愈 高，但台農73 號藷皮及藷肉之花青素含量均比芋心甘藷低。烘乾藷皮及藷肉之花青素 含量比冷凍乾燥大幅減少，但冷凍乾燥及烘乾會比新鮮材料分別提高10 倍及3-5 倍之 抗氧化能力。花青素含量與抗氧化能力無正相關存在，而與總酚含量呈正相關，但大幅 提高花青素含量，對甘藷抗氧化能力有幫助，更可豐富甘藷色彩，增進甘藷多樣性利用， 所得結果可供新品種紫肉甘藷台農73 號之利用及未來育種方向參考。Anthocyanidin composition and antioxidant activity of sweet potato (Ipomea batatas (L.) Lam) storage roots with plentiful colors were studied. The results showed that cyanidin and peonidin were synthesized in purple-red skin and storage root, and more anthocyanidins were found in darker color ones. The skin and storage root of Tainung 73 cultivar contained less anthocyanidin than that of Purple sweet potato. 70℃ drying had less anthocyanidin content of skin and storage root than freeze drying, but freeze-drying and 70℃ drying increased antioxidant activity 10 times and 3-5 times respectively as compared with fresh materials. Antioxidant activity was positively correlated to total phenolic content, but not to anthocyanidin content. However, increased anthocyanidin content was good for enhancing antioxidant activity of sweet potato. The results could be applied as a reference for the utilization of Tainung 73 cultivar and future breeding of sweet potato

Microstructures of starch granule, starch digestibilities and predicted glycaemic index of common bean mutants in Taiwan

In this study, the microstructure of starch granule and in vitro starch digestibility were compared in de-coated seeds of common bean variety Hwachia and its NaN3-induced mutants. Significant differences in starch granule size (between 17.92 and 27.00 μm), total starch content (between 436.5 and 456.8 mg per seed) and resistant starch content (between 51.6 and 203.3 mg per seed) were found among mutants. Both boiling and autoclaving decreased resistant starch content in processed common beans. Significant difference in predicted gylcaemic index (pGI) (between 48.82 and 64.55%) for processed beans also existed among mutants. However, 96 h of 4 °C storage increased resistant starch content in processed common beans, possibly resulted from starch retrogradation during storage. Mutants SA-05, SA-08 and SA-31, which have smaller seed weight and lower pGI (average of 50.08%) compared to Hwachia (pGI of 57.05%), can be used to produce common bean based low GI dietary carbohydrate

Comparisons of flavonoids and anti-oxidative activities in seed coat, embryonic axis and cotyledon of black soybeans

Flavonoids contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activities and the ferric-reducing antioxidant power (FRAP) were compared in three black soybean varieties CRWD, Tainan 3 and Tainan 5. Varietal differences in antioxidant contents existed among the tested varieties. Variety CRWD accumulated more total phenolics (7.49 mg g−1) and isoflavones (1.77 mg g−1) than varieties Tainan 3 (7.05 mg g−1 total phenolics and 1.58 mg g−1 isoflavones) and Tainan 5 (4.38 mg g−1 total phenolics and 0.63 mg g−1 isoflavones). CRWD also accumulated more proanthocyanidins in seed coat than Tainan 3 and Tainan 5. CRWD also demonstrated greater DPPH and FRAP activities than the other two cultivars. Stepwise regressions indicated that both DPPH and FRAP activities were correlated well with the total contents of phenolics and flavonoids, with total phenolics being the most important anti-oxidative factor. The present results indicate that CRWD has greater anti-oxidative responses than Tainan 3 or Tainan 5, and is useful in functional food and other applications

Expression of granule-bound starch synthase in developing rice grain

The expression of granule-bound starch synthase (GBSS) in rice (Oryza sativa) genotype Tainung 67 (200 g kg−1 grain amylose content) and its two NaN3-induced mutants SA419 and SA418 were examined. G/T polymorphism analysis indicated that SA418 (300 g kg−1 grain amylose content) carried Wxa allele. The insertion of 23 base pairs sequence was found only in SA419 (80 g kg−1 grain amylose content), suggesting that it was a waxy mutant. Microsatellite polymorphisms (CT)n were also detected on the Wx gene encoding GBSS in the tested genotypes. The activities of several key enzymes involving starch biosynthesis in developing grains of field-grown rice plants were also compared during grain filling period. Significant genotypic differences were only found in the expression of GBSS. The content of amylose in SA418 grain was higher than Tainung 67 and SA419 grains throughout the entire grain filling period, possibly due to its superiority to synthesize amylose through GBSS. The lowest amylose content of SA 419 grain was attributable to its extremely low activity of GBSS in comparison with the two other genotypes. The mutation effects on the expression of GBSS were confirmed by two-dimensional electrophoresis and mass spectrometry. Copyright © 2007 Society of Chemical Industr

In vitro inhibitory effects of cranberry bean (Phaseolus vulgaris L.) extracts on aldose reductase, α-glucosidase and α-amylase

The in vitro inhibitory activities of different seed extracts prepared from cranberry bean mutant SA-05 and its wild-type variety Hwachia against aldose reductase, α-glucosidase and α-amylase were examined. The results indicated that the polyphenolics-rich extracts obtained using 800 g kg−1 methanol and 500 g kg−1 ethanol demonstrated inhibitory activities against aldose reductase (IC50 of 0.36–0.46 mg mL−1) and α-glucosidase (IC50 of 1.32–1.94 mg mL−1). The 500 g kg−1 ethanol extracts also showed α-amylase inhibitory activities (IC50 of 70.11–80.22 μg mL−1). Subsequent extracts, prepared further with NaCl and H2O from precipitates of 800 g kg−1 methanol or 500 g kg−1 ethanol extracts, exhibited potent α-amylase inhibitory activities (IC50 of 17.68–38.68 μg mL−1). A combination of 500 g kg−1 ethanol extraction plus a subsequent H2O extraction produced highest polyphenolics and α-amylase inhibitors. The SA-05 α-amylase inhibitor extracts showed greater inhibitory activities than that of Hwachia. Thus, cranberry bean mutant SA-05 is an advantageous choice for producing anti-hyperglycaemic compounds

Optimization of somatic embryogenesis in suspension cultures of horsegram [Macrotyloma uniflorum (Lam.) Verdc.]—A hardy grain legume

Cell suspension cultures were established from immature cotyledon derived calli from drought tolerant legume horsegram [Macrotyloma uniflorum (Lam.) Verdc.]. Embryogenic callus could be originated from cut slices of the immature cotyledons on MS solid medium [Murashige, T. Skoog, K., 1962. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant. 15, 473–497] augmented with 1.0 μM zeatin and 4.5 μM NAA. Numerous somatic embryoids (26.4%) appeared on MS liquid basal nutrient medium with 5.6 μM NAA and with absence of zeatin during 3 weeks culture. Sustained cell division resulted in the formation of cell aggregates, and then progressed to globular, heart and further if they differentiate properly to torpedo and cotyledonary stages within 5 weeks. Transfer of individual embryos on to a fresh MS basal medium with no plant growth regulators was able to achieve complete maturation. Only a relatively few number of embryos developed into root/shoot when transferred to 0.9 μM GA3, 15 g/l−1 sucrose and 2.4 g/l−1 gelrite containing medium. Substitution of sucrose associated with the use of l-glutamine gave, in the range of concentrations tested, the strongest enhancement of the embryo growth and development. About 5% of somatic embryos were converted into true-to-type fertile plants

Comparisons and selection of rice mutants with high iron and zinc contents in their polished grains that were mutated from the indica type cultivar IR64

Developing rice varieties biofortified with iron (Fe) and zinc (Zn) is an important strategy to alleviate nutritional deficiencies in developing countries, where polished rice is consumed as the staple food. In this study, the contents of several macro- and micro-minerals in polished rice grains of cultivar IR64 and its 254 sodium azide-induced mutants (M8 generation) were assessed. The results indicated that the contents of potassium, phosphorus, calcium, magnesium, iron, manganese, copper, and zinc varied among the tested mutants. The polished rice grains of mutants M-IR-75 and M-IR-58 accumulated more Fe (28.10 and 27.26 mg kg−1, respectively) than cultivar IR64 (3.90 mg kg−1). Mutant M-IR-75 also produced higher yield (average of 8.65 ton ha−1 over two crop seasons) than cultivar IR64 (average of 7.27 ton ha−1). Mutants M-IR-180, M-IR-49 and M-IR-175 contained more Zn (26.58, 28.95 and 26.16 mg kg−1, respectively) than cultivar IR64 (16.00 mg kg−1), but only mutant M-IR-180 showed a grain yield comparable to cultivar IR64. Thus, the mutant M-IR-75 can be recommended to rice growers to produce Fe-rich rice grains. Additionally, the high-Fe (M-IR-75 and M-IR-58) and high-Zn (M-IR-180, M-IR-49 and M-IR-175) mutants can be used as genetic resources for rice improvement programs