Production of a useful mutant by chronic irradiation in sweetpotato

Sweetpotato cultivar Kokei No. 14 was planted in a ⁶⁰Co gamma field. Shoot apices from the plants irradiated with different doses were cultured on MS medium supplemented with 2.0 mg/l 2,4-D for the induction of embryogenic calluses and the formation of somatic embryos. Embryogenic calluses with somatic embryos were transferred to MS medium supplemented with 1.0 mg/l ABA to induce the germination of somatic embryos. Plantlets from somatic embryos developed into whole plants on the basal MS medium. The regenerated plants were transplanted in a field and from them one mutant with alteration of root flesh color and yield was obtained. The root flesh color had changed from light-yellow in the wild-type plant into orange in the mutant. The yield of storage roots increased significantly from 218.8 ± 60 g (FW) in the original plant to 646.9 ± 150 g (FW) in the mutant per plant. Carotenoids content of the storage roots in the mutant had significant difference compared to the wild-type at the 1% level. Peroxidase isozymes and RAPD polymorphism were also analyzed between the mutant and the wild-type plants.     

晋甘薯3号高产栽培技术研究

１９９４～１９９７年，对晋甘薯３号的施肥量、密度、扦插期进行了试验。结果表明，晋甘薯３号的最佳施肥量为Ｎ１１３１～１３８６ｋｇ／ｈｍ２，Ｐ２Ｏ５１１６２５～１２８５５ｋｇ／ｈｍ２，Ｋ２Ｏ３６８１～４３５９ｋｇ／ｈｍ２；合适的密度为５２５００株／ｈｍ２，适宜的扦插期为４月２５日左右。执行这套方案，甘薯产量可达４５０００ｋｇ／ｈｍ２左右。     

离子束对甘薯胚性悬浮细胞团的辐射诱变效应

以甘薯品种栗子香为材料,用0～100 Gy 12C5+和0～200 Gy 4 He2+离子束分别照射其胚性悬浮细胞团,结果表明栗子香胚性细胞团适宜的12C5+和4He2+辐射剂量分别为30～50 Gy和50～70 Gy。对辐照后的材料进行培养,通过体细胞胚胎发生途径获得大量再生植株。将获得的再生植株移栽到大田,对其地上部和地下部特征进行分析,发现离     

淀粉型甘薯品种直链淀粉含量、糊化特性和乙醇发酵特性的关系

以15个淀粉型甘薯品种为试验材料,测定其直链淀粉含量、糊化特性和乙醇发酵特性,并分析它们之间的差异和相互关系。结果表明,不同甘薯品种的干物率、淀粉含量和直链淀粉含量(AC)均存在较大差异,相关分析表明,AC与干物率、淀粉含量之间呈极显著正相关;不同品种甘薯的糊化特性之间存在一定差异,但RVA谱特征值之间关系密切;不同甘薯品种的乙醇发酵特性之间也存在较大差异,乙醇含量与发酵强度之间呈极显著正相关。进一步分析表明,AC与RVA各特征值之间相关性不显著,而干物率、淀粉含量与糊化温度(PT)均呈极显著正相关(相关系数分别为r=0.661, P<0.01; r=0.670, P<0.01);AC与乙醇含量、发酵强度之间有显著正相关关系(相关系数分别为r=0.653, P<0.01; r=0.698, P<0.01),但与发酵效率、发酵黏度的相关性不显著;发酵黏度与崩解值(BDV)呈显著负相关(r= –0.563, P<0.05),与消减值(SBV)显著正相关(r=0.639, P<0.05),而乙醇含量、发酵效率和发酵强度与淀粉RVA各特征值之间的相关性均不显著。聚类分析将15个品种分为3大类,第I类品种AC和BDV均较高,第II类品种的AC最高、BDV最低,而第III类品种AC最低、BDV最高。甘薯的AC和BDV可以作为评价甘薯乙醇发酵特性的指标,同时较高AC和BDV值应是燃料乙醇专用甘薯品种的选育方向。     

甘薯源库关系建立、发展和平衡对氮肥用量的响应

以盆栽、田间微区和田间裂区试验分析不同氮肥用量对苏薯16(半直立株型)和苏薯11(匍匐株型)生长前期(0~30 d)、中期(30~60 d)和后期(60~120 d)根系形态、单株薯数、叶面积指数、茎叶生物量、根生物量和T/R值的影响。结果表明,在全生育期内,施氮对甘薯茎叶生长均有显著促进作用,但对根生长的影响各不相同。生长前期,低量施氮对根系生长和分化有促进作用,而适量和高量施氮则表现显著抑制作用,并使30 d时单株薯数显著降低29.3%~36.6%或1.3~2.0个(P0.05),但同一甘薯品种、不同施氮处理的单株薯数在生长中期之后又趋于一致。生长中期,适量和过量施氮可显著促进源库规模的发展,并使甘薯茎叶生物量增加量分别显著提高35.5%~48.9%和73.4%~79.8%(P0.05),叶面积指数迅速达到4左右,而对根生物量增加量无显著影响(P0.05)。生长后期,施氮过多时(N32处理)茎叶鲜重持续增加,到收获时叶面积指数和蔓薯比分别达4.9~5.6和1.50~1.51,显著高于适量施氮处理时的3.3~3.5和0.58~0.64(P0.05);施氮过少时(N30处理)则反之,收获时不施氮处理的叶面积指数和蔓薯比分别为1.6~1.9和0.36~0.42,其中叶面积指数显著低于适量施氮处理(P0.05);不同施氮处理的单个薯重差异越来越大,适量施氮处理的单个薯重(218~345 g)显著高于不施氮(181~262 g)和过量施氮处理(160~285 g,P0.05),所以适量施氮处理的最终单株块根产量(1.02~1.20 kg)也高于不施氮处理(0.88~0.91 kg)和过量施氮处理(0.79~0.87 kg,P0.05)。表明,移栽前一次性基施氮的条件下,不施或少施氮有利于甘薯生长前期源库关系的提早建立,适量或过量施氮有利于甘薯生长中期源库关系的发展,而仅有适量施氮有利于维持甘薯生长后期的源库平衡。     

分子生物学技术在甘薯中的应用

甘薯是重要的粮食作物,它的遗传背景复杂,分子生物学研究进展落后于水稻、玉米等作物。分子标记技术主要应用于甘薯的遗传图谱构建、遗传多样性分析以及亲缘关系分析等方面。目前,已经构建了数张遗传图谱,亲缘关系分析表明三浅裂野牵牛I.trifida与甘薯有很紧密的亲缘性。基因克隆技术已经应用于甘薯在抗逆、品质以及块根发育等相关基因的分离,为甘薯的分子育种带来了有益的目的基因。在栗子香、新大紫等甘薯品种有转基因的报道,采用农杆菌介导的方法,已经取得了少量的转基因植株。     

不同生态环境对甘薯主要品质性状的影响

为研究甘薯鲜薯总胡萝卜素、淀粉、蛋白质、还原性糖和可溶性糖等主要块根品质特性在不同地区的生态变异,选用"徐薯25"与"徐22-5"杂交所获得的不同甘薯基因型,在4个生态点进行栽插试验,系统分析不同生态环境下甘薯块根主要品质性状的变异规律。结果表明:生态点、年份、基因型、地点×基因型互作、年份×基因型互作对甘薯鲜薯总胡萝卜素、淀粉、蛋白质、还原性糖和可溶性糖的影响均达到显著水平。胡萝卜素表现为基因型×环境互作效应大于基因型效应和环境效应,而其他品质性状均表现为环境效应远大于基因型效应和基因型×环境互作效应;可溶性糖和蛋白质含量的年际效应明显大于基因型主效应或基因型×年份互作效应,而其余3个品质性状的基因型×年份互作效应大于基因型主效应或年份主效应。在4个生态点中,徐州点的胡萝卜素、还原性糖和可溶性糖含量最高,但淀粉含量最低;烟台点的蛋白质含量最高,胡萝卜素含量最低;南昌点的蛋白质含量最低,胡萝卜素含量最高;万州点的还原性糖和可溶性糖含量最低,上述品质性状随纬度变化的规律不明显。值得关注的是,不同环境下,蛋白质含量为烟台点>徐州点>万州点>南昌点,表现出随纬度升高而增大的趋势。不同年份处理间,2008年的胡萝卜素、还原性糖及可溶性糖含量高于2009年,而2008年的淀粉和蛋白质含量低于2009年。淀粉、可溶性糖含量变幅范围在2年间差别不大,而其他3个性状变幅范围在2年间差别较大。各甘薯基因型在不同地点、不同年份间品质性状的变异中,以胡萝卜素变异系数为最大,淀粉变异为最小。     

Rural income generation through improving crop-based pig production systems in Vietnam: Diagnostics,interventions, and dissemination

Sweetpotato-pig production is an important system that generates income, utilizes unmarketable crops, and provides manure for soil fertility maintenance. This system is widely practiced from Asia to Africa, with many local variations. Within this system, pigs are generally fed a low nutrient-dense diet, yielding low growth rates and low economic efficiency. Our project in Vietnam went through a process of situation analysis, participatory technology development (PTD), and scaling up over a seven-year period to improve sweetpotato-pig production and to disseminate developed technologies. The situation analysis included a series of pig production assessments in several provinces in northern and southern Vietnam, and pig supply-market chain identification was conducted in 13 provinces. The analysis of these studies informed the project of the following: (1) appropriate locations for our activities; (2) seasonal available feedstuff and farmers feeding practices; (3) market fluctuation and requirements; and (4) feeding and management improvement needs based on which the subsequent phase of PTD was designed. The PTD involved a limited number of farmers participating in sweetpotato varietal selection, sweetpotato root and vine silage processing, seasonal feeding combination, and pig feeding with balanced crop-feed diet and silage. Six years of multi-location and multi-season sweetpotato selection resulted in a few promising varieties that yielded up to 75% more dry matter and have since been formally released. The most significant results of silage processing and feeding trials include improved growth, higher feeding efficiency, increased year-round local feedstuff, and considerable labor reduction from eliminated cooking and vine cutting. Once these technologies were developed, a farmer-to-farmer training model was designed for scaling up the adoption and impact. Farmer trainers from seven communes in seven provinces received training in these technologies. In turn, they undertook the responsibility of training other farmers on sweetpotato selection, processing, and feeding. An impact study was also administered to monitor and evaluate (M&E) the dissemination process and to document the impact of the new technologies and farmer-to-farmer training model on pig growth and farmer income generation. The results showed that both participating and non-participating farmers have taken up the technologies, although the former demonstrates higher rates of adoption than the latter. The participants also generated more income and saved more labor from the adoption of the technologies. While the scaling up and M&E activities are on-going, the project has since broadened from a sweetpotato-pig system perspective to a pig-cropfeed system perspective based on farmers needs. It has included other crop feeds such as cassava and peanut stems in the research portfolio. New technologies based on on-going PTD will continuously be incorporated into the future training curriculum.Dai Peters is currently a senior scientist with the International Center for Tropical Agriculture (CIAT) based in Hanoi, Vietnam. This publication is based on research conducted while she was a research scientist with the International Potato Center (CIP). She holds a PhD from North Carolina State University. Her research interests include on-farm participatory research methodologies, agroenterprise development, and sweetpotato-pig farming systems in Vietnam and Papua, Indonesia. Her recent publications include a manual on crop-based pig feed systems, post-harvest fermentation of sweetpotato roots and vines, and agroenterprise development.Nguyen Thi Tinh is currently a coordinator of the sweetpotato-pig improvement project at the International Potato Center in Vietnam. Ms. Tinh holds a Masters degree in animal nutrition from Wageningen University, Netherlands. She participated in the project on pig feeding trials for five years.Mai Thach Hoanh is a sweetpotato breeder with the Root Crop Research Center of Vietnam Agricultural Science Institute (VASI). He holds a PhD in sweetpotato breeding from the same institute. He participated in the project for seven years on sweetpotato selection. Nguyen The Yen is a crop scientist in the Food Crop Research Institute of Vietnam. He holds a PhD in sweetpotato breeding from VASI. He participated in the project for five years on sweetpotato selection.Pham Ngoc Thach is a lecturer with the Hanoi Agricultural University. He holds a PhD in veterinarian science from the same university. He participated in the project for five years in controlling pig diseases during the feeding trials.Keith Fuglie is a regional coordinator and research scientist in the International Potato Center based at Bogor, Indonesia. He holds a PhD in agriculture economics from the University of Wisconsin. He designed the impact study for the project.     

不同施磷量对鲜食型甘薯产量及磷素吸收的影响

采用田间试验的方法,设置了6个磷水平(0,37.5,75.0,112.5,150.0,187.5kg/hm²),研究不同施磷量对鲜食型甘薯产量、干物质积累和磷素积累的影响。结果表明,施磷能够显著增加甘薯产量并提高商品薯率,当施磷量为P205112.5kg/hm²时增产幅度最大。施磷水平对甘薯干物质积累与分配有显著影响,在甘薯各生长时期施磷条件下块根干物质积累量和积累速率整体上均显著高于不施磷处理(P<0.05),同时施磷还提高了地下部干物质分配比率,促进了块根产量的形成。施用磷肥可以显著提高甘薯对磷素的积累,随着施磷量的增加,甘薯植株的磷积累量呈现增加趋势。     

南方甘薯新品种比较试验

以广薯87为对照,通过品比试验,分析了新近引进（选育）的福薯21、泉薯10号等9个南方甘薯新品种的产量、薯块品质、抗病性等性状,并评述了其在生产和育种上的利用价值：泉薯10号、福薯21、金薯2号可作为高产鲜食品种推广,桂粉3号和龙薯14宜作为优质高产品种推广。