氮肥形态及氮钾施用措施对水稻生长 和养分吸收的影响

为探明不同氮（NH4-N和NO3-N）源下，不同施钾水平及氮钾施用次序对水稻生长和养分吸收的影响，进行了温室盆栽试验。结果表明：在水稻生长早期（20d左右时），以NO3-N作为N源时水稻的生物产量和氮钾养分吸收量均显著高于NH4-N作N源的处理，但随着生长时期的延长，NH4-N源更能促进水稻的生长和养分吸收，因此，从整个营养生长时期来讲，铵态氮肥作为水稻N源更具有优越性。结果同时表明，氮肥施用效果与钾肥的施用水平有很大关系，在一般盆栽试验氮肥用量（纯N用量0.15 g/kg）水平下，施钾（K2O）量达到0.51g/kg时会导致水稻的生长及养分吸收量显著下降。铵钾施用次序对水稻的营养生长及养分吸收均有一定的影响，特别是施钾量较高时，铵钾在土壤中的交互作用会导致水稻因氮素供应不足而影响生长和养分吸收。     

江苏省的菜用大豆新品种及其高产栽培技术研究

为了鉴定在江苏省鲜食大豆区域试验中表现优良的新品系的丰产性，抗病性和适应性，为大面积种植提供适合江苏栽培的新品种，通过最近6年的区域和生产试验，共审定春夏不同季节栽培的菜用大豆新品种8个，极大地推动了江苏省菜用大豆新品种的推广与种植。本文主要介绍了目前在两种不同生长季节的菜用大豆的主栽品种，并对目前江苏不同季节菜用大豆主栽品种的相关栽培技术进行了研究。     

用不同类型的水稻鉴别品种鉴定江苏稻瘟病菌的致病性

根据DNA指纹图谱和系谱, 从1999年采集的96个江苏稻瘟菌株中选择44个菌株进行致病性测定. 它们被鉴定为7个生理小种. 用日本清泽系列单基因鉴别品种和LTH近等基因系(NILs)鉴别品种分析, 分别产生27和10个致病类型, CO39 NILs对江苏菌株几乎没有鉴别作用. 分析结果可见供试菌株之间致病性差异极大. 研究表明, 发展包含较多抗病     

应用SSR分子标记分析国外种质对我国小麦品种的遗传贡献

利用363对SSR标记分析了在我国小麦生产和育种中发挥了重要作用的11份国外引进品种和33份选育品种的遗传组成,旨在揭示国外种质对我国小麦品种改良的遗传贡献,指导种质资源引进和利用。国外种质包含了选育品种所发现等位变异的76.3%。与不同时期小麦品种等位基因多样性比较发现,国外种质的平均等位变异数最多(3.92),20世纪60年代(2.86)和70年代(3.01)基本一致,80年代有所升高(3.46)。品种间遗传距离比较与品种等位基因多样性结果相吻合。比较引进和选育品种在SSR位点的等位变异频率变化,发现至少在33个SSR位点,国外种质等位变异在我国小麦育种中被优先选择(该等位变异在引进和选育品种的分布频率均高于70%),其中一些位点已知与产量、生育期和抗病等性状密切相关。表明引进品种在以上基因组区域对我国小麦品种具有非常高的遗传贡献。     

不同品种马铃薯的颗粒全粉功能品质分析

以相同条件下生产的7个品种马铃薯为原料,测定其品质指标(干物质、总淀粉、直链淀粉、还原糖、VC)和加工全粉的功能指标(蓝值、持水性和持油性),研究不同品种马铃薯及其所制颗粒全粉功能品质的差异。结果表明,除费乌瑞它品种马铃薯的干物质含量偏低外,其余6个品种秦芋30、秦芋32、0406-1、0406-9、安薯56、鄂5均符合加工全粉的要求;马铃薯原料中总淀粉含量高,则游离淀粉的含量相对较高。7个品种马铃薯全粉的蓝值顺序为:安薯56费乌瑞它鄂5秦芋320406-9秦芋300406-1;持水性顺序为:秦芋32鄂5秦芋300406-9费乌瑞它0406-1安薯56;持油性顺序为:0406-1安薯56鄂5费乌瑞它=秦芋32秦芋300406-9。该结果可为马铃薯颗粒全粉生产的原料选择和全粉应用提供参考依据。     

New strategies for increasing heterozygosity in crops: Vicia faba mating system as a study case

Our research assesses the feasibility of using artificial selection on pre-mating floral traits to modify the mating system of faba bean (Vicia faba). This analysis considered two synthetic populations, which were derived from different genetic pools and had undergone five years of multiplication. For these populations, we identified floral and inflorescence traits that influence outcrossing per plant and examined the relative importance of these traits in governing yield. Codominant isozyme loci and the mixed-mating model were used to estimate the multilocus female outcrossing rate. A maternal half-sib design was used to evaluate the additive genetic component of floral and inflorescence traits, yield and yield components. Multiple regression was used to assess the effects of floral and inflorescence traits on outcrossing and yield and components of yield. The two populations exhibited mixing mating. Self-fertilization appears to result from the action of pollinating bees, so that its incidence could be modified by selection on floral and inflorescence traits that affect pollination. Floral and inflorescence traits affected individual differences in outcrossing unequally, with most variation being associated with the numbers of displayed flowers and inflorescences. Variation among plants in reward traits and in shape, although statistically significant, had limited and inconsistent influences on individual differences in outcrossing. Yield and its components varied strongly with aspects of floral display and, to a lesser extent, floral design, except for seed weight. Overall, our results imply that both outcrossing and yield could be enhanced by selection for plants that produce more inflorescences, each with relatively few flowers.     

Response to long-term selection in early maturing maize synthetic varieties

Long-term continuous selection is essential for germplasm improvement. However, choice of germplasm for long-term genetic improvement might limit the success of germplasm enhancement programs. The objective of this research was to report the response to long-term selection in early maturing North Dakota (ND) synthetic varieties. We wanted to determine whether the performance of three ND maize synthetic varieties was improved by long-term mass selection (M) and if the performance of one of them was improved by long-term modified ear-to-row (MER) selection. The evaluation of long-term selection response was performed at two plant densities. An experiment in a randomized complete block design with split-plot arrangement was used to evaluate NDSM(M), NDSAB(M), NDSCD(M), and NDSAB(MER) under 75,000 and 42,500 plants per hectare across seven environments. Long-term mass selection for grain yield and stalk lodging resistance in NDSM(M), NDSAB(M), and NDSCD(M) was not successful, since there were no significant changes in grain yield or stalk lodging in these populations at either low or high densities. On the other hand, long-term modified ear-to-row selection was effective for grain yield improvement in NDSAB(MER). Grain yield increased non-linearly from 3.9 Mg ha⁻¹ in cycle 0 to 5.0 Mg ha⁻¹ in cycle 12 at a rate of 2.5% per cycle. Interaction between plant density and genotype was not detected even though selection was performed at relatively low densities (20,000 plants ha⁻¹ for mass selection and 50,000 plants ha⁻¹ for ear-to-row selection). The confirmation of a lack of interaction between plant density and genotype suggests that selection at low plant densities might still be able to provide high-density stress resistance through density-independent genotypes, allowing progeny testing across multiple locations with better accuracy and fewer resources. Selection methods that emphasize both additive and dominance effects such as full-sib recurrent selection are recommended to maximize genetic improvement of advanced population cycles of early maturing synthetics.     

Some remarks on carrot breeding (Daucus carota sativus Hoffm.)

Carrot breeding in the past 150 years has resulted in varieties with high yield, a short growing period, and excellent root colour. Recently, hybrid varieties have demonstrated good uniformity of roots, a quality accepted by most consumers. By contrast, only a few resistant varieties (mainly open-pollinated varieties) are offered by seed companies, most being resistant to Alternaria. Hybrid breeding offers a chance of combining good uniformity and different sources of resistance. Efforts in future breeding should concentrate on the improvement of health and the development of genotypes suitable for cultivation in suboptimal climates and regions, as well as for special applications.     

甘蔗新品种及主栽品种对褐锈病抗性与Bru1基因分子检测

The aim of this study was to assess brown rust resistance of new sugarcane varieties bred in China and main cultivated varieties in sugarcane planting area, and screen the elite new brown rust resistant varieties for popularization and application in production. In total, 60 new varieties in the national regional test of new sugarcane varieties were tested in Kaiyuan and Lincang, and 34 main cultivated varieties were studied in Lincang, Puer, and Yuxi, Yunnan province, and Yizhou, Guangxi province, China, where the incidence of brown rust was particularly high. The resistance of these sugarcane varieties to brown rust was investigated under natural inoculation and molecular marker-assisted identification was used to detect the brown rust resistance gene Bru1. The results of field survey showed that 66 (70.21%) of the 94 new and main cultivated varieties were highly resistant to moderately resistant, and 28 (29.79%) were susceptible to highly susceptible. Molecular detection indicated that Bru1 gene was found among 54 (57.45%) of the 94 new and main cultivated varieties. Some main cultivated varieties that were currently planted across large areas such as Guitang 29, Guitang 44, Dezhe 03-83, Liucheng 03-1137, Yuetang 60, and Guitang 46 were highly susceptible to brown rust, and 31 new varieties such as Yuegan 48, Funong 09-2201, Guitang 08-120, Liucheng 09-15, Zhongzhe 1, Yunzhe 08-1609, Yunrui 10-187, and Zhongtang 1201 were resistant. Therefore, in the sugarcane planting areas with high incidence of brown rust and wet and rainy climates, more effort should be eliminated the main susceptible varieties and promoted the application of new resistant varieties. This will help to achieve a reasonable distribution of varieties, fundamentally control the outbreak of disease in sugarcane planting areas, and provide security for the high-quality development of sugarcane industry in China in the future.     

水稻广亲和品种与籼、粳稻的亲和力遗传分析

分析了广亲和品种02428,CP—SLO_(17)和轮回422与籼、粳稻杂种F_1、F_2及F_3世代亲和力与颖尖色的遗传特点,结果表明,具有一个广亲和品种的组合,F_1花粉育性与结实率正常,均在70%以上,F_2结实率呈连续变异,但主要分布在60～80%区域,平均结实率65.1%,F_3育性变异度与F_2基本一致,但平均结实率有明显提高。两个广亲和品种间杂交后代育性显著提高,F_2结实率低于60%的单株较少,而不含广亲和品种的组合F_1表现半不育,F_2呈正态分布,平均结实率43.4%,主要分布在40～60%之间。以上说明广亲和基因是存在的,广亲和力既受主效基因支配,也有微效基因参与作用。颖尖色出现3∶1或9∶7分离,有色颖尖与高结实率连锁明显,因此,颖尖色可以作为选择广亲和基因的标记性状。