Studies on Genetic Behavior of the Interspecific Hybrid Progenies in Subgenus Soja

利用大豆 Soja 亞屬之栽培種(Glycine max)高雄選十號(KS10)、半栽培 種(G. gracilis)(Gr2)及野生種(G. soja)(So59)為親本, 進行G. max 與 G. soja 及 G. max與 G. gracilis 之種間正反雜交, 共獲得四個雜 交組合的F、F集團, 作為探討 Soja 亞屬內種間雜交後代育種行為之材 料, 結果分述如下: 1.G. max 與 G. soja 正反雜交兩組合之F植株的種 子產量與總乾重及反交F植株之株高等性狀都具明顯雜種優勢；但兩組合 之每粒數均呈負方向之雜種優勢。 2.G. max 與 G. soja 正反雜交兩組 合F集團之株高、分枝數、成熟日數、生殖生長日數、有效莢數、稔實率 、每莢粒數、主莖粒數、總乾重及收穫指數等性狀, 均呈超越兩親之分離 。 3.G. max 與 G. soja 正反交兩組合之株高、主莖節數、始花日數、 成熟日數、生殖生長日數、每莢粒數、主莖粒數、種子產量、總乾重及收 穫指數等性狀都具有較高之遺傳率(53%∼94%), 另反交組合之分枝數、生 殖生長日數/ 營養生長日數、有效莢數、稔實率、分枝粒數及總粒數等性 狀亦具有較高之遺傳率(55%∼88%), 但此些性狀在正交組合中遺傳率則偏 低(25%∼46%), 百粒重在正反交兩組合中, 均為遺傳率最低之性狀(5% 及 11%)。 4.遺傳型相關一般均高於表現型相關, G. max 與 G. soja正 反雜交兩組合中, 除正交之生殖生長日數/ 營養生長日數外, 其他性狀均 與種子產量呈顯著正相關；株高、分枝數、主莖節數三性狀與有效莢數、 主莖粒數、成熟日數、分枝粒數、總乾重、總粒數呈顯著相關。每莢粒數 與成熟日數及百粒重呈顯著負相關。 5.以性狀間表現型相關行主成分因 子分析並經 varimax rotation發現, G. max 與 G. soja 正反雜交兩組 合各性狀間的相關關係綜合表現相似, 與種子產量關係最密切之性狀為有 效莢數、分枝粒數、總粒數、總乾重, 其他性狀與產量關係不大, 株高、 分枝數、主莖節數、稔實率、主莖粒數及收穫指數等性狀間有密切關係

The Effect of Effective Heat Unit on Leaf Number Expression of Rice

本試驗以25個逢機選取自台灣地區過去育成的水稻品種爲材料，於1995年二期作 及1996年一期作進行田間試驗調查，探討有效熱單位對水稻葉齡表現之影響。試驗結果顯示一期作因葉片伸展期之氣溫較低，水稻達到劍葉抽出之日數較二期作爲長，但若以有效累稂熱單位表達，則一期作達劍葉抽出所需之量較二期作低。唯在兩期作中，移植後初期，及葉片伸展後期之單位葉齡及葉齡指數所需之有效累積熱單位較其它時期爲高。另分析不同生長期單位葉齡及葉齡指數伸長所需之有效累植熱單位，結果顯示兩期 作之生殖生長期均較營養生長期爲高，唯在期作間，營養生長期所需之有效累積熱單位 於二期作較一期作爲高，但生殖生長期則無顯著差異。 Twenty-five varieties were used to study the effect of effective heat unit on leaf number expression of rice. Effective heat unit sumlation (EHUS) of rice plants reached to flag leaf expansion in the 1st crop season were obviously lower than those of rice in the 2nd crop season. EHUS of early and late period of rice leaf expansion on per leaf number (LN) and leaf number index (LNI) were higher than other stages. Rice plants in reproductive growth period of the 1st and the 2nd crop seasons seemed to require higher EHUS for leaf expansion. While in the vegetative growth period of the 2nd crop season, the EHUS requirement for leaf expansion seemed higher than those of the 1st crop season

Solar radiation use efficiency and its discriminant functions of the rice varieties released un Taiwan

本研究之目的在建立台灣地區水稻稻穀產量之光能利用效率(RUEy)的判別函數，以作為選育高光能利用效率的水稻品種之用。由於產量之光能利用效率需涉及水稻植冠對日光輻射之截取能力，及植冠所截取之日光輻射形成稻穀產量之效率；因此，本試研究首先針對過去台灣地區過去六十年來育成的水稻品種進行植冠截光率(MLI)及光能利用效率的品種變異性分析，及其在不同育種年代中的遺傳演進，並進一步探討水稻植冠發育之相關性狀與MLI及RUEy的關係，作為建構判別函數所需之變數選擇的依據。 逢機選取25個過去六十年來台灣地區育成的水稻品種為材料, 進行水稻MLI之品種變異性及其遺傳演進之探討。結果顯示品種間雖具有顯著的變異性，但以兩期作之數據進行合併分析，水稻MLI之遺傳率及遺傳增進量均甚低，顯示水稻MLI是一個相當不穩定的性狀；但若在各期作內分別估算，則遺傳率及遺傳增進量均明顯地提高。其中以第二期作施用180公斤氮肥及第一期作不施氮肥的條件下之水稻MLI的育種效應顯著地比其他試驗條件下之育種效應高。此外，植冠發育之相關性狀與水稻MLI間均具有顯著的相關性，但以抽穗期之LAI與MLI關係最密切，可作為水稻品種選育的參考性狀；而此參考性狀在第二期作施予180公斤氮肥之環境下，具較高之遺傳率及遺傳增進量。 二十五個參試水稻品種之MLI值在第一期作下，並未依育種年代演進而呈顯著的改變。但在第二期作不施氮肥及施以180公斤氮肥的條件下, MLI值之遺傳增進量呈現直線減少的趨勢。另由參試品種之植冠平均截光效率(LIE)進行遺傳改良成果的週期性評估, 顯示台灣地區育成的水稻品種之LIE隨育種年代演進而增加或遞減的情形並不明顯, 換言之，老品種雖具有較高的MLI, 但其LIE並不高於新近育成的品種。 就RUEy而言，25個參試品種在第一期作之表現明顯高於第二期作，新近育成之品種的RUEy會因氮肥之施用而提高，而老舊品種在高氮肥的環境下則可能因倒伏而降低其RUEy。由綜合變方分析的結果顯示水稻RUEy為一相當穩定的性狀，品種與環境因子間並未呈現顯著地交感作用。就育種選拔效應而言，應以第二期作施用氮肥的環境下較高。由相關分析的結果顯示水稻RUEy與植冠發育相關性狀間關係並不密切。 不同年代育成的參試品種，在氮肥施用的環境下，RUEy值隨育種年代之演進而呈直線增加的趨勢，且增加的效應會因氮肥施用量之增加而提高，唯此種關係在不施氮肥環境下則不易顯現出來。 為了分析水稻穀粒產量的品種變異性，本試驗以總日光輻射截取量(LIsum)及產量之光能利用效率(RUEy)的乘積用以表達水稻稻穀產量。相同地，以總乾物重之光能利用效率(RUEtdw)及收穫指數(HI)之乘積用以表達RUEy。分析結果顯示當參試品種處以90公斤氮肥施用量時，LIsum對穀粒產量之變異性的影響較高；然而在施以180公斤氮肥或不施氮肥的環境下，則RUEy對穀粒產量之變異性較高。另就RUEtdw及HI對RUEy之變異性的影響而言，在各種氮肥施用量下，RUEtdw對RUEy之變異性的影響均大於HI。在此情況下，產量受制於RUEy的高比例變異均為透過RUEtdw所達成。 為使本研究所建立之判別函數能準確地鑑別一水稻品種之RUEy，先在各個試驗環境下進行供試品種的分群分析(clustering)，再以多變數變方分析決定分群之群數，以達到群內變異最小，群間變異最大的要求。結果顯示除第一期作90公斤氮肥施用量下可分為四群外，其它試驗環境下均以分成三群較為適當。建構判別函數之性狀，乃依因子分析之結果，選取在相同主因子中與RUEy關係密切之性狀。本研究依不同環境所建立之六組判別函數，均具有顯著的判別能力，可將低RUEy群明確地區隔出來，依此，在水稻品種選育的過程中，可清楚的鑑別低RUEy個體而予以淘汰，減少育種工作量，有利於選育工作之進行。Solar Radiation Use Efficiency and Its Discriminant Functions of the Rice Varieties Resealed in Taiwan Abstract This study aimed to explore a set of canonical discriminant functions, i.e., linear combinations of certain quantitative traits, that best reveal the difference of solar radiation use efficiency of grain yield (RUEy) among rice varieties. A total of 25 varieties randomly selected from the collection of rice varieties released in Taiwan during the past 60 years were used to conducted field experiments with various nitrogen rates and/or planting densities in the first and the second crop seasons through the years from 1997to1999. Plant height, tiller number, leaf area index , leaf inclination angle, light interception rate, and total shoot dry weight were periodically measured throughout the growing season, and grain yield and its components, i.e., panicle number, spikelet number per panicle, ripen rate and 1000-grain weight were also recorded at harvest. RUEy was calculated as the ratio of grain yield to the total intercepted solar radiation (LIsum), which in turn was the product of the total incoming radiation and the mean light interception rate (MLI). The MLI value of rice canopy, although significantly different among the test varieties, was unstable across the range of the experiments. Both the estimates of heritability (intra-variety correlation) and genetic gain of MLI were low from a combined analysis on the pooled data. When data were analyzed separately for each of the two crop seasons, however, the estimates of these two genetic parameters of MLI raised remarkably. It revealed that varieties with high MLI value might best be identified under the conditions of applying 180 Kg nitrogen per hectare in the second crop season or applying no nitrogen in the first crop season. As expected, many characteristics of the rice canopy were significantly correlated with MLI. Among them, the LAI at heading, which showed high heritability and genetic gain, was correlated with MLI very closely. This suggested that selection for variety with high MLI could be accomplished by the way of selection for LAI at heading. When grown with no nitrogen fertilizer or with 180 Kg nitrogen per hectare in the second crop season, the MLI of the test varieties showed a clear decreasing trend over the time the varieties were released. Such a time trend was not detected in the first crop season. Besides, no significant evolution pattern in the mean light interception efficiency (LIE), i.e., the ratio of MLI to LAI, was observed in the range of the experiments. In other words, the older varieties showed higher MLI but not higher LIE. All the test varieties gave higher values of RUEy in the first crop season than in the second crop season. The varieties released in recent years showed higher RUEy when they were fertilized with more nitrogen. But, the reverse was true for the old varieties. No significant GxE interaction was found in the analysis of variance of RUEy, which indicated that RUEy was a rather stable character of the rice varieties released in Taiwan. However, higher estimates of the heritability and genetic gain of RUEy were obtained when these varieties were fertilized with nitrogen in the second crop season. This suggested an efficient environmental condition for the selection of varieties with high RUEy. No significant correlation was detected between RUEy and other canopy characteristics investigated in this study. In general, the test varieties showed an increasing time trend of RUEy in respect to their breeding era . This trend was absent when these varieties were grown with no nitrogen fertilizer. To elucidate the varietal variation of grain yield and RUEy, grain yield was expressed as the product of LIsum and RUEy, which in turn was expressed as the product of radiation use efficiency of total dry matter production (RUEtdw) and harvest index (i.e., ratio of grain yield to total dry matter production, HI). The variance of grain yield was mainly accounted for by LIsum when the varieties were fertilized with 90 Kg nitrogen per hectare. However, RUEy took the role in determining the variation of grain yield when these varieties were fertilized with 180 Kg nitrogen per hectare or no nitrogen fertilization. On the other hand, contribution of RUEtdw to the varietal variance of RUEy was much higher than HI across the treatment levels of nitrogen rate. In sum, grain yield of a variety was mainly determined by its RUEy, which in turn was affected greatly by the RUEtdw of the variety when it was fertilized with certain amount of nitrogen. As a provision to develop the discriminant functions for RUEy, the test varieties were clustered, by a nonhierarchical clustering algorithm, into three to five groups according to their RUEy values evaluated in each of the six treatment combinations of the two crop seasons by the three levels of nitrogen rate. The optimal number of variety group was determined so as to maximize the among-group variance and to minimize the within-group variance of RUEy simultaneously. The result showed that the test varieties could adequately be separated into three groups except the treatments with 90 Kg nitrogen per hectare, which a four- group clustering seemed optimal. A set of two discriminat functions for RUEy were established for each of the six treatment combinations. Owing to their significant ability in identifying the varieties with low RUEy, a breeding program would be much more efficient to improve the RUEy of rice varieties if these discriminant functions were employed.目錄 章節 頁次 表目錄 ……………..…………………………………………………….Ⅰ 圖目錄 ………………..………………………………………………….Ⅴ 縮寫對照表 …………..………………………………………………….Ⅵ 中文摘要…………..…………………………..…………………………..1 第一章緒言……………..……………………..…………………………..4 第二章前人研究…………………………….…………………………….7 第三章水稻植冠結構與其截光率及光能利用效率之關係 一、前言……………………………….……….…….…………………..16 二、材料與方法…………………….……………..…………………….18 三、結果…………………………….……………………..……………..22 四、討論…………………………….…………………………..………..36 第四章水稻植冠截光率之品種變異性 一、前言……………………………….………………………………….40 二、材料與方法………………………………………………………….42 三、結果…………………………………………………………………..48 四、討論…………………………………………………………………..68 第五章水稻植冠之光能利用效率的品種變異性 一、前言…………………………………………………………………..73 二、材料與方法………………………………………………………….75 三、結果…………………………………………………………………..78 四、討論…………………………………………………………………..94 第六章水稻光能利用效率之判別函數的建立 一、前言……………………………….…………………………………101 二、材料與方法…………………………………………………………103 三、結果………………………………………………………………….106 四、討論………………………………………………………………….118 第七章綜合討論…………………………………………………………122 參考文獻………………………………………………………………….127 英文摘要………………………………………………………………….139 附錄………………………………………………………………………..14

(52(3):166-177)Yield and Grain Nitrogen Content in Relation to Leaf Color in Rice Cultivars TK 9 and TNG 67

本試驗於2000年在嘉義農業試驗分所之溪口試驗農場進行兩期作水稻試驗，參試材料為臺農67號及臺稉九號品種，為擴大水稻葉色變異範圍，利用三個氮肥等級 (0, 90, 180 kg N ha-1) 及三個栽植密度 (11.1, 22.2, 44.4 plant m-2，即行株距為3030, 3015, 1515 cm) 處理。葉色之測定工具為葉綠素計，水稻成熟期進行產量、產量構成因素及糙米氮素含量之調查，據以探討一、二期作水稻不同生育期葉色與稻穀產量及糙米氮素含量之關係。結果顯示：不同生育期水稻葉色值與單位面積稻穀產量之關係，以抽穗前後兩週最密切。水稻四個產量構成因素與不同生育階段之葉色值的關係，均不及產量與葉色值間密切。水稻葉色與糙米氮素含量間的關係，以抽穗期至抽穗後一週的相關性最高，兩期作不同生育期之葉色與糙米氮素含量均呈顯著的直線關係，唯關係密切程度稍有差異，本試驗結果顯示第一期作水稻抽穗期葉色與米粒氮素含量間的相關係數為0.80～0.91，而第二期作則為0.76～0.79，顯示兩者關係在一期作較為密切。This report studies the correlation relationship between the changes of leaf color during rice growth, grain yield and grain nitrogen content. Two rice (Oryza sativa L.) cultivars, TNG67 and TK9, were cultivated in the first and the second crop seasons, 2000. Three nitrogen rates (0, 90, 180 kg N ha-1) and three plant densities (11.1, 22.2, 44.4 plant m-2) were used to enlarge the variation of leaf color measured by chlorophyll meter (SPAD-520, MINOLTA). The results showed that the leaf color value in rice plant was significantly related to grain yield, especially two weeks before and after heading. The correlation between leaf color value and grain yield was closer than that of other four yield components. In addition, the leaf color in each crop season was linearly correlated to the nitrogen content of brown rice, particularly at the heading and one week later. The correlation coefficient for the first and the second crop was 0.80 to 0.91 and 0.76 to 0.79, respectively

Evaluation the potential utilization of feed grade rice for animal usage

一般水稻主要生產作為食用，水稻植株及莖桿、稻穀和米糠等也可以作為動物的食料，事實上取乳熟至黃熟期的稻株可作青貯料作為反芻動物的食料，其營養價值有如一般牧草青貯料。由於稻的種原豐富且具多樣性，本計畫擬篩選具高生產潛力之稻米品種(系)，評估其生產潛、飼料用品質以及總營養消化量，探討其作為飼料用途的潛能，以開發稻米生產的多元化利用。Animals are fed paddy rice and its by-products such as rice straw, rice hull, and rice bran. Whole rice plants can be fed to dairy and beef cattle as whole crop silage. Its nutritional value is almost equivalent to that of barley whole crop silages. This study was carried out to obtain basic information on variety selection and potential performance for the utilization of whole crop rice in Taiwan. Several varieties and elite lines were evaluated on agronomic performance and feed value such as total above-ground dry matter yield, acid detergent fiber, neutral detergent fiber, and total digestible nutrients to meet the potential utilization of rice for whole crop use

Integrated approaches for increasing water productivity and nitrogen utilization, and reducing methane emissions in irrigated rice

Rice (Oryza sativa L.) is one of the most important staples in the world. Seventy five percent of the world's rice is grown under flooded, or submerged conditions, it is also one of the biggest users of the world's developed freshwater resources. Water for agriculture, especially for irrigated rice production, is becoming increasingly scarce due to greater urban, domestic and industrial demand. Our challenge is to develop novel technologies and production systems that allow rice production to be maintained or increased in the face of declining water availability. Flooding of the soil is a prerequisite for sustained emissions of methane. Adequate drainage and water-saving irrigation greatly reduce methane emissions. Furthermore, it is not known how water-saving irrigation modifies nutrient use efficiencies and if it requires different N-fertilizer management compared with continuous flooding. This study was conducted to quantify and compare rice growth, yield, and methane emissions and water productivity under the commonly practiced water-saving irrigation and continuous flooding in typical irrigated rice environments in Taiwan. The comparison was carried out under different N-fertilizer management regimes to identify possible water by nitrogen interactive effects on nutrient uptake, nutrient-use efficiencies, and whether N-fertilizer management needs to be modified to fit the water regimes of water-saving irrigation compared with those of continuous flooding.稻為全球三大主要作物之一，全球稻米的生產約有75％來自於灌溉方式所栽培的水稻，在農作物的栽培中，水稻是所有作物中耗水量最大的作物。近年來，隨著氣候異常，加上都市化民生用水及工業化用水量激增，引發水資源運用分配的問題，因此改善農業用水資源利用的情形，才可達到農業永續經營的目標。現行水稻湛水栽培耗用大量水源，成為農業灌溉用水的最大宗，因此在水資源分配競爭的情況下，提升灌溉用水效率，發展節水栽培技術，對水稻的生產、糧食的供應相當重要。由於水田經營一般採湛水栽培，長期湛水栽培除耗費水資源外，湛水栽培易導致肥料隨著水滲漏、溢流而流失，降低肥料的可利用性；另外由於土壤長期處於浸水條件，易變成厭氧狀態，有利於甲烷生成菌分解有機質產生甲烷。為了提昇水稻的水份生產力，降低肥料的施用量以提高其利用效率，以及減少水田長期湛水的甲烷排放量，本計畫擬開發適合臺灣地區的節水栽培技術，配合減肥措施，評估節水栽培對肥料的利用效率以及對甲烷釋放量的影響，藉此發展出低投入、高效率的環境親合性栽培技術

Modelling the Phenology of Rice Varieties Released in Taiwan

此三年計畫之最終目標在建立一個系統模式, 以供模擬台灣地區育成的水稻品種之物候發育過程.在過去兩年, 利用自1989年至1998年所收集的數據進行回溯性的研究, 以及一項初步的驗證試驗.我們發現台農67號等六個品種在田間之自然條件下的感光性均甚低, 而且一個修飾後的溫熱單位模式可以相當合理地模擬這些品種的發育過程.本年度我們將在台灣環島幾個農業改良場所, 進行該模式的田間現場測試與驗證; 並將以本年度所獲得之數據進行模式的校正.若有需要, 則將進行模式的修正與改良, 以提高模式的模擬準確性與適用範圍.The ultimate goal of this three-year project is to build a system model for simulating the phenological development of the rice varieties released in Taiwan.During the past two years, via a retrospective analysis on the data collected from 1989through 1998and a preliminary validation experiment, we have found that the photoperiod sensitivity of six rice varieties popular in Taiwan seemed negligible when grown under natural field condition and a modified heat-unit model could simulate the developmental process of these varieties quite well.In this year, attempts will be made to test and validate the simulation ability of this model in field experiments at some Agricultural Experiment Stations around Taiwan.The model will then be calibrated by the data thus collected.And, when necessary, modification and refinement will be called for to enhance the precision and applicability of this phenology model

(43(2):135-142)Studies on the Panicle Density of Rice Ⅱ. Relationships between the Constructed Characters of Panicle and Grains Yield Per Hill

以25個穗著粒密度相異的稉稻品種（系）為材料探討11個稻穗構成性狀間的關係，結果發現一期作高單株產量之材料，具有穗重較重、一次枝梗平均粒數、二次枝梗數、二次枝梗總粒數、每穗粒數等較多、稔實率高與穗長較長等特徵，顯示穗型較大、粒數較多之材料，較能發揮高產之潛能：二期作高單株產量之材料群則為穗重、二次枝梗數、二次枝梗總粒數、每穗粒數與穗長中等者有較高產量表現。此外，一期作穗著粒密度雖與單株產量呈高正相關關係，然由主成份因子分布圖中顯示，高穗著粒密度者其單株產量並不一定高。Twenty five rice entries with different types of panicle density were used as materials to study the relationships between the 11 constructed characters of the panicle and grain yield per hill under Chaiyi environment conditions. In the first rice crop season, result revealed that entries with high yielding capacity pontenial were charactered by heavier panicle weight, a lot of average grain number per primary branch, secondary branch number per panicle, total grain number of secondary branches, total grain number per panicle, higher seed set and larger factor of panicle length. This might infer that the entries with high yielding pontenial in first crop season are largely due to heavier panicle weight and lots of grain number. On the other hand, in second crop season, entries with high yielding pontenial were along with reasonable panicle weight, secondary branch number per panicle, total grain number of secondary branches total grain number per panicle, and factors of panicle length. This might conc-lude that the entries with high yielding pontenial are mainly associateed with medial constructed characters of the panicles. A significant Positive correlat-ion between panicle density and grain yield per hill was found from the present studies However, as shown in the scattrer diagram of principal factor analysis, thar entries with higher panicle density were not always along with higher grain yield per hill was also observed. These suggest that the relationships between the constructed characters of the panicle and grain yield per hill is unjustifiable from the present data