The flavor of small immature tubers compared with mature Katahdin tubers

The flavor quality of seven immature potato samples (three varieties, four numbered selections) was found to be ‘equal to’ or ‘poorer than’ the flavor of mature Katahdin tubers stored for 10 months at 45 F (7.2 C). The samples were evaluated by a panel of 21 experienced judges.     

Tolerance to potato leafhopper inSolanum tuberosum L. gp. Tuberosum clones

We identified clones inSolanum tuberosum L. gp. Tuberosum breeding populations that, although susceptible to infestation by potato leafhopper,Empoasca fabae (Harris), exhibited a tolerance which was manifested by the ability to produce higher than expected tuber yields when heavily infested with leafhoppers. Such tolerance was noted in a number of clones in varying degrees, but one, B6930-1, was exceptional. It sustained only a 19% loss in tuber yield compared to ‘Katahdin,’ a susceptible cultivar, that averaged 33% lower tuber yields under similar infestation levels. We studied the seasonal growth patterns of this clone and compared them to those of Katahdin, and B6705-10, a breeding clone with known resistance to leafhopper infestation. We found that much of B6930-l’s tolerance results from its early, vigorous vine growth and its early and rapid rate of tuber bulking, enabling this clone to escape some of the effects of leafhopper feeding, whereas Katahdin was usually just beginning to tuberize at the height of leafhopper infestation.     

Influence of slitted polyethylene mulch,nitrogen rates,and trickle irrigation on potatoes

In 1974, potatoes(Solanum tuberosum L.) were grown on unmulched, clear, and black slitted polyethylene. Production and tuber specific gravity of the potatoes were determined at four nitrogen rates (0, 75, 150 and 225 lb/A) and with two varieties (Superior and Katahdin). In 1975, potatoes were grown on unmulched and clear slitted polyethylene with and without trickle irrigation. Nitrogen increased marketable yields up to 150 lb/A on the unmulched potatoes. Irrigation increased the marketable yields of potatoes on both unmulched and mulched plots. However, no advantage was found in marketable yields, specific gravities or tuber sizes of the potatoes grown on either clear or black slitted polyethylene mulch over conventional unmulched soil for the ‘Superior’ or ‘Katahdin’ varieties.     

快中子辐照对花生种子胚小叶植株再生的影响

以花生品种花育22号的成熟饱满种子为试材,采用14Mev不同剂量的快中子(0、9.7、14和18Gy) 进行辐照处理。处理后的种子经表面杀菌后,取胚小叶作为外植体先后在添加2,4-D 和BAP 的培养基上进行培养,诱导体胚形成及其萌发和植株再生。结果表明,体胚诱导率和植株再生率因辐照剂量的不同表现出明显的差异,随辐照剂量的增加,外植体形成体胚的频率及再生植株的频率明显降低。推断快中子辐照花育22号的适宜剂量为9.7~14.0Gy。再生小苗经无菌嫁接驯化后移栽田间,得到了成熟种子。           

薄壳山核桃‘Shaoxing’和‘Pawnee’花粉活力及储藏特性研究

以薄壳山核桃‘Shaoxing’和‘Pawnee’的花粉为材料,采用MTT染色法对其4个散粉时期的花粉活力及不同储藏条件下的花粉活力变化进行了研究,筛选出最佳花粉收集时期和最佳储藏条件。结果表明：（1）‘Shaoxing’和‘Pawnee’不同散粉时期花粉活力由高到低变化规律都为：散粉盛期>散粉初期>即将散粉期>散粉末期。（2）‘Shaoxing’和‘Pawnee’各散粉期的花粉活力随阴干时间的延长而下降,其中‘Shaoxing’盛花期、‘Pawnee’散粉初期的花粉在0~4 d的短时间阴干储藏下降速率最慢,96 h后分别仍有45.70%和64.31%;（3）低温、干燥的储藏条件有利于‘Shaoxing’和‘Pawnee’花粉活力的保持,2个品种的花粉在不同储藏条件下都表现为：?80 ℃密封干燥>?80 ℃密封>4 ℃密封干燥>4 ℃密封>常温密封干燥>常温密封,其中2个品种的花粉在?80 ℃条件储藏30 d后活力仍保持在60%以上,而常温条件储藏30 d后的花粉活力低于20%,储藏80 d就完全失去活力。     

澳系睡莲花粉离体萌发及低温保存研究

为研究适宜睡莲花粉离体萌发的培养基和低温保存的方法,以睡莲品种‘默笙’和3份原种睡莲的花粉为试验材料,采用单因素、正交试验设计,筛选出最适宜的培养基,观测睡莲花粉在不同温度下保存的萌发率。结果表明,4种澳系睡莲花粉的最适培养基的各组分浓度不同,花粉的生活力存在差异,澳洲原生浅色睡莲与澳洲原生深色睡莲的花粉生活力较高,分别为43.90%和45.63%;‘默笙’睡莲的花粉生活力次之,为31.84%;‘白巨睡莲’的花粉生活力较低,为9.73%;4种澳系睡莲花粉均不耐贮藏,不同温度下保存72 h后萌发率均为0。本研究结果可为睡莲杂交育种的亲本选择、花粉的低温保存研究提供参考。     

Seed transmission of potato spindle tuber virus

Seed transmission of potato spindle tuber virus (PSTV) has special significance for potato breeding programs. Transmission of PSTV has been reported to occur via true seed. Test families in the Frito-Lay breeding program were obtained from self- and cross-pollinations to determine the incidence of infected seedlings from healthy and diseased parents. Diseased seedlings from PSTV-infected Katahdin selfed were scored by visual and tomato index procedures as 100% and 87% infected, respectively. A similar result was obtained among seedlings from the cross of PSTV-infected Sebago x PSTV-infected Katahdin. Symptoms of PSTV infection were not detected by either method among seedlings from healthy Katahdin, selfed. The Frito-Lay, Inc., potato breeding program employs a number of phyto-sanitary procedures to exclude or reduce the possibility of PSTV contamination and spread.     

The Green Fence of Chinese Hibiscus (Hibiscus rosa-sinensis L.) Prevents Pollen Dispersal of Transgenic Rice (Oryza sativa)

Abstract

Transgene escape mediated by pollen dispersal is one of the preeminent concerns about genetically modified crops, including rice. In this study, the rice pollen donor of non-glutinous Oryza sativa ssp. japonica cv. ‘Tainung 67’ [TNG 67] had a greater potential of pollen flow, which was shown by the greater quantity, germination rate, and viability of pollen, than the other rice pollen donor of transgenic AAN. The pollen-mediated gene flow was detected by the frequency of outcrossed seeds in a “checker-board pattern” and alternating row arrangement of rice pollen donor (TNG 67 or AAN) and pollen recipient (glutinous rice ‘TNG 73’) in the fields. We conducted field experiments to assess rice pollen dispersal with or without a “green” fence of Chinese hibiscus, Hibiscus rosa-sinensis L., of approximately 2 m in height and 0.6 m in thickness. Without a green fence, the outcrossing rate of TNG 73 seeds decreased with increasing distance from the pollen donor, from 1.68% at 1 m to 0.01% at 35 m, with no outcrossing beyond 40 m. The outcrossing rate varied with the direction of pollen donor, from 0.05% in the northeastern direction to 0.78% in the southern direction, which was caused by prevailing wind direction. With the green fence, no seeds of TNG 73 were outcrossed. Since a buffer zone of at least 40 m is needed to prevent outcrossing of rice by pollen dispersal in an open field, planting of Chinese hibiscus around the rice field as a green fence would be an effective measure for preventing transgene escape mediated by pollen flow.     

花粉活力对澳洲坚果初始坐果率的影响

为了解花粉活力对澳洲坚果初始坐果率的影响,以高产品种‘南亚2号’和低产品种‘B3/74’为材料,对2个品种的花粉活力及初始坐果率进行了测定和分析。结果表明,‘南亚2号’花粉活力较强,其初始坐果率也较高。‘南亚2号’的花粉染色率和花粉萌发率分别达到89.0%和33.3%,显著高于‘B3/74’的56.7%和8.1%,其柱头上附着的花粉粒数量及花粉萌发量也显著多于‘B3/74’,‘南亚2号’的初始坐果率为10.9%,显著高于‘B3/74’的9.0%。      

Effects of Mulch and Potato Hilling on Development of Foliar Blight (<Emphasis Type="Italic">Phytophthora infestans</Emphasis>) and the Control of Tuber Blight Infection

Foliar and tuber blight caused by Phytophthora infestans accounts for significant losses in potatoes in field and storage. Nevertheless, limited research has been published on the effects of cultural practices on late blight control. Field experiments were conducted in two years on Howard gravely loam soil in New York State to evaluate the effectiveness of mulching using oat straw and hilling in preventing tuber blight infection for cvs Allegany and Katahdin. Potato hilling and mulching had little effect on foliar blight development. The cultivar affected the disease development in the foliage, with cv. Allegany showing lower foliar late blight than cv. Katahdin. Tuber blight incidence averaged 25% for cv. Allegany and 3% for cv. Katahdin in hilled plots, while in the mulched plots the incidence of tuber blight averaged 33% for cv. Allegany and 10% for cv. Katahdin. The straw hay mulch was ineffective in tuber blight control. Tubers set at a soil depth of more than 7 cm had lower tuber blight incidence than shallow tubers set at a depth of less than 7 cm. In both years, hilling provided partial protection of tubers but its effectiveness was limited in the presence of favourable conditions for late blight development. Even though large hills had proportionally a lower tuber blight incidence than medium-sized hills, the difference between the different hill sizes was not significant. These studies suggest that the use of cultivars with foliage resistance to late blight in combination with cultural practices may partially reduce the incidence of tuber blight. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation for endorsement by Cornell University or the US Department of Agriculture.     

不同茶梅品种杂交亲和性分析

为了解茶梅品种间杂交亲和性并为其亲本选择选配提供理论依据，以 12 个茶梅品种为材料，采用不规则配组 法共配对 72 个组合，开展了花粉活力比较及杂交亲和性试验。结果表明，有 66 个杂交组合能结实（91.7%），每个组 合平均结实率为 28.63%，其中 14 对组合杂交亲和性强（结实率在 50%以上），并以‘晚霞’ב银元’的杂交亲和性 最好（结实率达 100%），43 对组合杂交亲和性较强（结实率在 10.0%~46.2%），9 对组合的杂交亲和性较差（结实率 低于 10%）；另有 6 对杂交组合无法获得杂交果实（8.3%）；花粉活力对杂交亲和性有一定的影响，但杂交亲和性与 花粉活力没有必然的因果关系。供试茶梅品种中，‘有希’作为杂交父本或母本的亲和性均表现较强，‘乙女’、‘秋 芍药’、‘昭和之荣’作为杂交母本的结实性较强，‘东红牡丹’、‘丹玉’、‘银元’、‘堪次郎’作杂交父本可 增强母本结实性，‘晚霞’具有适合作杂交母本的单一偏向性。     

Incidence and severity of powdery scab on potatoes in Pennsylvania

Studies were conducted in Potter Co., Pennsylvania to investigate the effect of powdery scab (Spongospora subterranea) on five potato cultivars (Norchip, Rosa, Kennebec, Katahdin, and Monona) at two planting dates. Soil temperature was within the range of 15–18 C and soil moisture was within 15–19% based on dry weight throughout the season. The effect of planting date was significant at each disease assessment, except for the severity on the fourth assessment. By the end of the season, incidence of scab was 66% or more for all cultivars. Rosa, Kennebec and Katahdin had a greater scab incidence over both planting dates and a greater severity at the first planting date than Monona and Norchip.     

Some storage characteristics of potato cultivar Atlantic

The cultivars Atlantic, Kennebec and Katahdin were compared as to their storability and cooking qualities for the storage seasons 1974–75 and 1975–76. The studies show Atlantic was equal to Katahdin and Kennebec with regard to storability, except that at storage temperatures above 40°F (4.5°C) for 6 months, sprouting was excessive. Storage losses due to Fusarium tuber rots from natural infection were higher in Atlantic than either Katahdin or Kennebec. The processing quality for chips and French fries of Atlantic was equal or slightly better when compared to the other varieties tested.     

Sensory quality of Ontario potatoes compared with principal varieties grown in Maine

Baked potatoes of five varieties grown at the same location in Maine were evaluated for quality shortly after harvest and after six months’ storage by sensory panels of 16 and 18 members. The Ontario variety was rated significantly poorer (P = 0.05) in flavor than Russet Burbank, Katahdin, and Superior, but did not differ from Kennebec when tested in November. Following storage, however, these differences were not significant. At the 1% level of detection, Ontario tubers were judged significantly less mealy than those of the Russet Burbank, Katahdin, Superior, and Kennebec varieties (Nov. Kennebec excepted) and were grayer (Mar. Superior excepted). Due to the low mealiness ratings and grayness of flesh, tubers of the Ontario variety were considered less desirable for table stock than potatoes of other principal varieties grown in Maine.     

不同茶梅品种杂交亲和性分析

为了解茶梅品种间杂交亲和性并为其亲本选择选配提供理论依据，以 12 个茶梅品种为材料，采用不规则配组法共配对 72 个组合，开展了花粉活力比较及杂交亲和性试验。结果表明，有 66 个杂交组合能结实（91.7%），每个组合平均结实率为28.63%，其中 14 对组合杂交亲和性强（结实率在 50%以上），并以‘晚霞’ב银元’的杂交亲和性最好（结实率达 100%），43 对组合杂交亲和性较强（结实率在 10.0%~46.2%），9 对组合的杂交亲和性较差（结实率低于 10%）；另有 6 对杂交组合无法获得杂交果实（8.3%）；花粉活力对杂交亲和性有一定的影响，但杂交亲和性与花粉活力没有必然的因果关系。供试茶梅品种中，‘有希’作为杂交父本或母本的亲和性均表现较强，‘乙女’、‘秋芍药’、‘昭和之荣’作为杂交母本的结实性较强，‘东红牡丹’、‘丹玉’、‘银元’、‘堪次郎’作杂交父本可增强母本结实性，‘晚霞’具有适合作杂交母本的单一偏向性。     

Oxidative discoloration of potato tuber tissue related to translucency of processed dice

In 1965 and 1966 potato clones from Maine, New Jersey, Ohio and Wisconsin field tests were evaluated subjectively for the translucent appearance of processed dice in milk and were examined colorimetrically for the degree of oxidative discoloration. There was a highly significant positive correlation between discoloration and translucency. The effects of time and location were minimized by relating each clone to the values for Katahdin in corresponding plots. By setting arbitrary selection limits of 40% and 75% of the Katahdin mean optical density, it was found that the method could be used for either selection of low-translucency or rejection of high-translucency types. Values less than 40% were generally acceptable, greater than 75% unacceptable and intermediate values were inconclusive. A scheme is presented whereby this method, in combination with a soluble protein method, was applied to several clones.     

Effect of time and date of inoculation,plant age,and temperature on translocation of potato leafroll virus into potato tubers

Movement of potato leafroll virus (PLRV) to tubers following placement of viruliferous aphids on foliage was studied on the medium-maturing cultivar, Katahdin and the late-maturing cultivar, Russet Burbank. Inoculation was begun on August 20 and continued at three-day intervals until mid-September. There was no trend of increasing or decreasing numbers of leafroll-infected tubers from early to late inoculation. Several variables were examined to determine their effects on the incidence of PLRV-infected tubers. Multiple regression analyses showed that inoculation date, maximum daily temperature, minimum daily temperature, plant age, and length of time from inoculation to harvest explained 38% of PLR incidence in tubers of cv. Katahdin. Length of time from inoculation to harvest and minimum daily temperature explained 40% of PLR incidence in tubers of the cv. Russet Burbank.     

在蒙导条件下转bar基因水稻与无芒稗间的基因漂移

以转基因水稻Y0003和99-t为父本,无芒稗为母本,在蒙导条件下研究转基因水稻与无芒稗间潜在的基因漂移可能性。用光学显微镜观察了用不同方法（紫外灯照射,反复冻融,黑暗放置）制备的蒙导花粉蒙导条件下转基因水稻花粉在无芒稗柱头上的萌发生长情况,并与无芒稗自花授粉的情况相比较。结果表明,在供试的所有蒙导花粉蒙导条件下,两种转基因水稻的花粉在无芒稗柱头上虽能萌发,但花粉管扭曲成各种形状而不能进入无芒稗柱头。与无芒稗自花授粉的花粉萌发生长有极明显的差异。杂交也不结实。说明蒙导花粉不能克服转基因水稻和无芒稗的不亲和性,转基因水稻与无芒稗间基因漂移的可能性极小。     

Effects of the number of pollen grains on cold tolerance at the booting stage in rice lines with QTLs for cold tolerance

This study was conducted to clarify the relationship between the number of pollen grains per anther and spikelet fertility under low temperature conditions in the rice cultivars and lines including lines with quantitative trait loci (QTL) for cold tolerance, adapted to the Tohoku region of northern Japan. Cold-water treatment decreased anther length, the number of pollen grains per anther, and spikelet fertility in all cultivars and lines. The number of pollen grains was proportional to anther length in all cultivars and lines and under all temperatures. Spikelet fertility decreased with decreasing the number of pollen grains in cold-water treatments at 18.5 and 19.3?°C. ‘Ouu 415’, with the qLTB3 QTL for cold tolerance, had 28% more pollen grains and 9% higher spikelet fertility than the recurrent parent, ‘Hitomebore’, in the 18.5?°C cold-water treatment, suggesting that qLTB3 increased both parameters. Lines with the qCTB8 QTL for cold tolerance had significantly more pollen grains in two of the three years and significantly higher spikelet fertility in all three years in the 19.3?°C cold-water treatment, suggesting that qCTB8 reinforced cold tolerance. Ctb1, a proposed cold-tolerance QTL, had no effect on the number of pollen grains or spikelet fertility. In conclusion, the cultivars and lines with more pollen grains had a higher cold tolerance. Some of QTLs were inferred to increase the number of pollen grains and reinforce cold tolerance.     

Testing maine potato seed stocks in Florida for presence of virus X

Seed lots of the ‘Katahdin’ cultivar originating from the Maine Seed Potato Board’s program to eliminate potato virus X (PVX) were tested for PVX content. Leaf samples were selected from test lots grown in south Florida at the Maine Department of Agriculture’s Florida Seed Testing Farm. In 1971 and 1973 samples were brought back to the laboratory at Presque Isle, Maine where tests were conducted both serologically and onGomphrena globosa. In 1972 serological tests were conducted in Florida and samples were also brought back to Maine. In 1974 tests usingG. globosa were conducted at the farm site in Florida. Considerable variation in PVX content among lots was found in each year of testing, demonstrating the need for a routine yearly testing program for PVX. Experiments conducted in Florida in 1975 suggest that use of composite sampling methods can facilitate the handling of a much larger volume of tests each year.