Variation in cooking and eating quality traits in Japanese rice germplasm accessions

The eating quality of cooked rice is important and determines its market price and consumer acceptance. To comprehensively describe the variation of eating quality in 183 rice germplasm accessions, we evaluated 33 eating-quality traits including amylose and protein contents, pasting properties of rice flour, and texture of cooked rice grains. All eating-quality traits varied widely in the germplasm accessions. Principal-components analysis (PCA) revealed that allelic differences in the Wx gene explained the largest proportion of phenotypic variation of the eating-quality traits. In 146 accessions of non-glutinous temperate japonica rice, PCA revealed that protein content and surface texture of the cooked rice grains significantly explained phenotypic variations of the eating-quality traits. An allelic difference based on simple sequence repeats, which was located near a quantitative trait locus (QTL) on the short arm of chromosome 3, was associated with differences in the eating quality of non-glutinous temperate japonica rice. These results suggest that eating quality is controlled by genetic factors, including the Wx gene and the QTL on chromosome 3, in Japanese rice accessions. These genetic factors have been consciously selected for eating quality during rice breeding programs in Japan.     

美国引进水稻资源的主要性状比较研究

1998年以来,从美国农业部戴尔帮佩国家水稻研究中心,引进水稻资源778份。通过隔离检疫后,以中国恢复系明恢复63作为对照,选择美国、哥仑比亚、韩国、巴西、意大利五个国家培育的生育期与对照接近的水稻品种各10个。对其主要的产量与品质性状,进行了田间试验与实验室考种,对试验资料进行了统计分析。结果表明:引进的品种产量都比中国四川目前栽培的品种低,但品质普遍较优。这些品种都不能够直接用于生产,但作为育种亲本材料有一定利用价值。     

结缕草属植物的抗旱性初步评价

以目前生产上广泛应用的‘兰引3号’结缕草、‘青岛结缕草’和马尼拉为对照,对48份结缕草种源的表征永久萎蔫系数(APWI)进行了测定并分析,结果如下:1)各种源的APWI的变异范围为8.7 8%~1 3.4 1%,变异系数为9.10%。在48份供试种源中,APWI显著低于‘兰引3号’结缕草的有6份种源;APWI显著低于马尼拉的有2份种源;APWI显著低于‘青岛结缕草’的有15份种源;APWI同时显著低于3份对照的有2份种源。结缕草属植物的APWI存在极显著的差异。2)结缕草属植物不同种的APWI不同,其排序为:中华结缕草>大穗结缕草>结缕草>沟叶结缕草=细叶结缕草,其中变异系数最大为结缕草。3)APWI在结缕草、中华结缕草种内存在着极显著的差异,且结缕草种内抗旱性差异明显高于中华结缕草种内差异。4)结缕草属植物的APWI与经度和纬度均未发现显著相关;结缕草、中华结缕草种内的APWI与经纬度也未发现显著的线性相关。     

Chromosome number in germplasm accessions of Paspalum (Plicatula group) from different regions in Brazil

We determined the chromosome number of 52 accessions of Paspalum from the germplasm collection of the Centro de Pesquisa de Pecuária do Sudeste (CPPSE/EMBRAPA) originating from different regions in Brazil. All accessions belonged to the Plicatula group, 13 of them being P. plicatulum, three P. guenoarum, two P. yaguaronense, two P. compressifolium, one P. atratum, and 31 still unidentified Paspalum sp. Except for a P. yaguaronense accession that presented 2n=60, all the remaining ones presented 2n=40 chromosomes. This is the first report of the chromosome number of P. atratum. Considering that the basic number for most species in the genus Paspalum is ×=10, the accessions analyzed are tetraploids (2n=4×=40) and hexaploids (2n=6×=60). This revised version was published online in July 2006 with corrections to the Cover Date.     

空间诱变柱花草品系比较试验

利用空间辐射技术选育柱花草新品种(系).空间辐射柱花草种子使其后代发生突变,经连续4a接种鉴定,选育出85个株系进行试验研究.结果表明,85个株系中30个株系的牧草产量、旱季干物质产量、抗病性、长势和植株存活率表现优良,其中2001-71,2001-2,2001-80,2001-84,2001-81,2001-24以及2001-73的综合测度值极显著高于其群体,有可能成为取代其亲本热研2号柱花草而在生产上推广利用的新品系.     

Genetic diversity and population structure of Brachiaria brizantha (A.Rich.) Stapf accessions from Ethiopia

Brachiaria is a tropical, warm-season grass native to Africa. It is an extensively cultivated forage in the tropics with proven benefits on livestock productivity. Brachiaria is well-known for high biomass production, animal nutrition, carbon sequestration, biological nitrification inhibition, soil conservation, and adaptation to drought and low fertility soils. However, the use of Brachiaria grass for fodder production in Africa has been little explored largely due to lack of cultivars suitable to different production environments. The exploration and use of natural diversity is fundamental for an efficient Brachiaria breeding program. We analysed genetic diversity and population structure of 112 Ethiopian Brachiaria brizantha accessions using 23 microsatellite markers. A total of 459 alleles were detected with an average polymorphic information content of 0.75 suggesting high discriminating ability of these markers. The molecular variance analysis showed a high contribution (86%) of within-cluster differences to the total variation. Three allelic pools revealed by STRUCTURE analysis in 112 accessions were in agreement with the clustering patterns seen in neighbor-joining tree and principal coordinates analyses. A core collection of 39 B. brizantha accessions was constituted. This study concludes a high genetic diversity of Ethiopian B. brizantha accessions and their importance in Brachiaria breeding programs.     

Association of holidays, full moon, Friday the 13th, day of week, time of day, day of week, and time of year on case distribution in an urban referral small animal emergency clinic

Objective – To interrogate the association of variables: day of week, time of day, day of the year (major holidays, Friday the 13th, and the full moon), and month of year with the caseload of an urban academic emergency service.
Design – Retrospective study.
Setting – Urban small animal teaching hospital emergency clinic.
Animals – Cats and dogs that were presented to the emergency clinic.
Interventions – None.
Measurements and Main Results – The hospital computer database was searched for all visits to the Emergency Service of the Mathew J. Ryan Veterinary Hospital of the University of Pennsylvania from January 1, 1987 through December 31, 2002. Variables included in the electronic data were date of admission, time of day of admission, species (dog or cat), hospital service the case was transferred to for ongoing care and whether the case was discharged directly from the emergency service. The association of caseload with day of week, time of day, day of the year (major holidays, Friday the 13th, and the full moon), and month of year was described and statistically evaluated. Saturdays and Sundays were the busiest days of the week and significantly increased caseload was noted for the majority of holidays (except Easter Day and Thanksgiving Day) with Memorial Day being the busiest. Midweek evenings as well as Saturday and Sunday afternoons were the busiest periods of the day. There was no association with caseload and Halloween, the full moon, or Friday the 13th.
Conclusions – The busiest times were midweek evenings, Saturday and Sunday afternoons, and most major holidays.     

不同自然分布区刺梨遗传多样性的RAPD分析

 收集了 4省 30个野生刺梨样品 ,采用 16个随机引物扩增的RAPD标记 ,对不同自然分布区刺梨的遗传多样性进行分析。这些引物共产生 94条带 ,其中 6 2条 (6 5 .96 %)表现多态性 ;样品的多态性百分率、样品组合的相似系数及聚类分析结果都表明 ,来自贵州的样品蕴藏有最丰富的遗传多样性 ,贵州的刺梨是进一步遗传改良最重要的遗传资源 ;而川西的 5个样品的遗传差异性最小 ;来自鄂西高海拔地区的 3个样品具有较高的遗传差异性 ,其果实性状上表现出很大的特异性 ,在刺梨的新品种培育上显示了特殊价值。     

229份杧果种质对炭疽病抗性初步评价

炭疽病是杧果的重要病害,严重影响杧果的生长势以及杧果的产量和质量,选种抗病品种是有效的防治方法之一。采用室内离体叶片抗病性鉴定法,初步鉴定了在农业部儋州杧果种质资源圃中的229份杧果种质对炭疽病的抗病性。结果表明,在参试的种质中未发现免疫和高感种质,其中高抗种质13份、中抗种质36份、中感种质116份、感病种质64份,这些种质的初步评价,为进一步展开杧果抗病遗传规律及分子育种研究打下了基础。     

Diversity of boron-toxicity tolerance in lentil growth and yield

Boron (B) toxicity is increasingly being recognized as a problem in arid areas of West Asia, where lentil is widely grown. This study investigated whether or not: (1) phenotypic variation of B-toxicity tolerance exists at the seedling stage in lentil, (2) such variation persists to affect adult performance, and (3) there is geographical diversity in seedling tolerance. Four experiments were conducted in a greenhouse. Boric acid was added and mixed uniformly into the soil-mix to prepare high-B soil. Experiment I screened 77 lentil lines randomly selected from ICARDA's international nurseries. Visual growth scores and foliar B-toxicity symptom scores were taken 4–5 weeks after sowing, and used as an indicator for B-toxicity tolerance. In Experiments II and III, four selected lines were studied beyond the seedling stage. In Experiment IV, 231 lentil accessions from seven different countries/regions of the world were screened. There were highly significant differences between the 77 lines in B-toxicity tolerance at the seedling stage as indicated by their degree of B-toxicity symptom, and plant growth. The two tolerant and two sensitive selections from Experiment I showed diverse performance up to maturity as reflected by their differences in leaflet loss, dry mass reduction, and seed yield when grown in high-B soil. There were significant differences in B-toxicity tolerance between the 231 accessions. On average, accessions from Afghanistan were the most tolerant, followed by those from India, Iraq, Syria, Europe, Ethiopia, and Nepal.