甘蔗光周期诱导开花和杂交利用研究

本文报道了１９９８年度云南省甘蔗研究所光周期诱导甘蔗开花及杂交利用结果。本研究以４月１日和６月１日两种起始处理时间,１２ｈ２５ｍｉｎ和１２ｈ１５ｍｉｎ两种固定日长处理,于１０月１日起日递减光３０ｓ至抽穗时止的光周期诱导技术分别对７个难花亲本和７个常用亲本进行了开花诱导。结果表明：在不同的光周期处理下,粤糖５７／４２３、Ｃｏ４１９、闽糖７０／６１１、罗汉蔗等４个难花亲本被诱导开花;７个常用亲本全部孕穗或开花,并提早花期３－４个月。利用诱导开花亲本分别与割手密（Ｓ．ｓｐｏｎｔａｎｅｕｍ）、斑茅（Ｓ．ａｒｕｎｄｉｎａｃｅｕｍ）、滇蔗茅（Ｅ．ｒｏｃｋｉ）、芒（Ｍ．ｓｉｎｅｎｓｉｓ）、河八王（Ｎ．ｐｏｒｐｈｙｒｏｃｏｍａ）等野生种成功地进行杂交或远缘杂交,获得大量实出苗,为野生资源的利用及优良品种的选育奠定了基础。     

Effects of photoperiod on salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relation between salsolinol (SAL)‐induced prolactin (PRL) release and photoperiod in goats. A single intravenous (i.v.) injection of SAL was given to adult female goats under short (8 h light, 16 h dark) or long (16 h light, 8 h dark) photoperiod conditions at two different ambient temperatures (20°C or 5°C), and the PRL‐releasing response to SAL was compared to that of thyrotropin‐releasing hormone (TRH) or a dopamine (DA) receptor antagonist, sulpiride. SAL, as well as TRH or sulpiride, stimulated the release of PRL promptly after each injection in both 8‐ and 16‐h daily photoperiods at 20°C (P < 0.05). The area under the response curve (AUC) of PRL for the 60‐min period after injections of saline (controls), SAL, TRH and sulpiride in the 16‐h daily photoperiod group was greater than each corresponding value in the 8‐h daily photoperiod group (P < 0.05). There were no significant differences in the AUC of PRL among the values produced after the injection of SAL, TRH and sulpiride in 16‐h daily photoperiod group; however, the values produced after the injection of TRH were smallest among the three in the 8‐h daily photoperiod group (P < 0.05). The PRL‐releasing responses to SAL, TRH and sulpiride under a short and long photoperiod condition at 5°C resembled those at 20°C. These results show that a long photoperiod highly enhances the PRL‐releasing response to SAL as well as TRH or sulpiride in either medium or low ambient temperature in goats.     

Diel Rhythms of Serum Metabolites and Thyroid Hormones in Red Porgy Held in Different Photoperiod Regimes

Diel rhythms in serum glucose, lactate, cholesterol, triglycerides and thyroid hormones were studied in red porgy, Pagrus pagrus, held under different photoperiod regimes (constant darkness – DD, 8L:16D,12L:12D), at a constant temperature (17.1–18.7 °C) and fed with commercial pellets, by means of a self-feeder. A clear diurnal rhythm in feeding activity, regardless of the photoperiod regime was demonstrated. All serum components showed significant diel rhythms, although they were not necessarily consistent or circadian in periodicity. As well as this, differences in the average values among the varying treatments were observed. Fish held under the 12L:12D protocol displayed significantly higher average T₄, T₃ and lactate levels during the day rather than at night. Maximum glucose values occurred 8–12 h after dawn and maximum lactate concentrations at 06:00 or 14:00 h. Diel variations in cholesterol were evident only in the DD group with peak values inversely correlated with the rhythm of food intake. Triglycerides displayed a similar pattern of changes. Significant diel fluctuations in T₄ serum levels were observed only in fish exposed to the 12L:12D protocol, with peak values at dawn. A clear diurnal peak (10:00 h) in T₃ concentrations was observed in fish subjected to the 12L:12D regime, while fish exposed to the 8L:16D protocol showed two peaks: one in the photophase (10:00 h) and another in the scotophase (02:00 h). The light–dark alternation and the general activity rhythm of fish seem to be the main synchronizers of the diel rhythms observed in this study.     

Is the nutritive value of tall fescue (Festuca arundinacea Schreb.) related to the accumulated forage mass?

The aim of this work was to investigate whether neutral detergent fibre (NDF) and dry‐matter digestibility (DMD) are related to tall fescue accumulated forage mass (AFM) and to assess the relevance of environmental variables to predict the nutritive value of tall fescue swards. Three experiments were carried out in Pergamino, Argentina. To obtain swards with different amounts of AFM, two N levels and two irrigation regimes were applied in the spring after sowing and the autumn of the next year. In spring and autumn, AFM, NDF and DMD were measured every 10–12 days. In spring, NDF increased from 503 to 604 g kg^?1, DMD decreased from 684 to 558 g kg^?1 and AFM increased from 0·64 to 2·82 t DM ha^?1. In autumn, NDF decreased from 543 to 442 g kg^?1, DMD increased from 591 to 681 g kg^?1 and AFM increased from 0·35 to 1·10 t DM ha^?1. The results show that the nutritive value of tall fescue through the year is not related to the accumulation of dry matter of the sward. Nutritive value is determined by the reproductive stage in late spring and early summer, the fate of photosynthates at different times of the year and the synthesis of non‐digestible compounds.     

同光周期红光对油葵芽苗菜生长和品质的影响

采用发光二极管（light emitting diode,LED）精确调制红光（630 ± 20）nm的光强及光周期,研究不同光周期LED红光对油葵芽苗菜生长和品质的影响。结果表明：随着光周期从0延长至12 h · d-1,油葵芽苗菜下胚轴长显著降低,子叶面积显著增加;而随着光周期从0延长至16 h · d-1时,芽苗菜叶绿素和类胡萝卜素含量显著提高;全株鲜质量和淀粉含量在光周期为16 h · d-1时均有显著提高;维生素C的含量随光周期延长呈现逐渐提高的趋势,而游离氨基酸含量、SOD和CAT活性均呈现降低趋势。总体而言,红光光周期设置在16 h · d-1时有利于促进油葵芽苗菜生长和部分品质改善。     

短日照诱导对小豆生长发育、光合和荧光参数的影响

为明确短日照对小豆生长发育、光合和荧光参数的影响,采用不同生育时期短日照诱导处理来调查小豆的形态指标、开花时间及开花节位,在开花期和结荚期测定光合作用和叶绿素荧光。结果表明,与对照相比,短日照诱导使小豆的株高降低、平均茎粗和主茎节数变小、白红2号在开花期和结荚期的节间长度升高,唐山红小豆降低;短日照诱导使小豆的花期提前并降低开花节位;短日照诱导使2个品种的净光合速率在开花期明显升高,在结荚期降低,气孔导度、细胞间CO2浓度和蒸腾速率在开花期无明显变化,在结荚期,白红2号明显降低,唐山红小豆升高;短日照诱导对开花期的叶绿素含量无明显影响,在结荚期明显降低,与对照相比,白红2号在开花期和结荚期的Fv/Fm升高,唐山红小豆在开花期变化规律不明显,在结荚期升高;短日照诱导使小豆的产量构成因素及产量呈下降趋势。以上结果说明短日照诱导对花荚期小豆的生长发育、光合参数及产量具有调控作用。     

太湖流域晚粳品种抽穗期的遗传分析

 设置人工长短日照、高低温环境对太湖流域20份晚粳水稻品种的光、温敏感性及基本营养生长期进行分析,结果表明,这20份晚粳品种都表现出强感光性,而且多数品种基本营养生长期较短,具有较强的感温性,抽穗期长短与品种的感光性呈显著正相关。利用一套抽穗期主基因近等基因系分析这些晚粳品种的抽穗期基因型,结果表明, 太湖流域晚粳品种几乎都同时携带主效显性感光等位基因E1和显性早熟等位基因Ef 1,在E2位点主要为非感光等位基因e2,在E3位点,部分品种携带感光等位基因E3或E3t;在Se 1位点,携带的主要是非感光等位基因Se 1e,还有部分品种为主效显性感光等位基因Se 1n;另外,大部分品种还携带可以部分抑制Se 1、E1表达的隐性感光抑制因子hd2。     

Thoughts and Practice on Some Problems about Research and Application of Two-Line Hybrid Rice

The main problems about research and application of two-line hybrid rice were reviewed, including the confusing nomenclature and male sterile lines classification, the unclear characteristics of photoperiod and temperature responses and the unsuitable site selection for male sterile line and hybrid rice seed production. In order to efficiently and accurately use dual-purpose genic male sterile lines, four types, including PTGMS (photo-thermo-sensitive genic male sterile rice), TGMS (thermo-sensitive genic male sterile rice), reverse PTGMS and reverse TGMS, were proposed. A new idea for explaining the mechanism of sterility in dual-purpose hybrid rice was proposed. The transition from sterile to fertile was involved in the cooperative regulation of major-effect sterile genes and photoperiod and/or temperature sensitive ones. The minor-effect genes with accumulative effect on sterility were important factors that affected the critical temperature of sterility transfer. In order to make better use of dual-purpose lines, the characterization of responses to photoperiod and temperature of PTGMS should be made and the identification method for the characterization of photoperiod and temperature responses of PTGMS should also be put forward. The optimal ecological site for seed production could be determined according to the historical climate data and the requirements for the meteorological conditions during the different periods of seed production.     

QTL analysis of photoperiod sensitivity in common buckwheat by using markers for expressed sequence tags and photoperiod-sensitivity candidate genes

Photoperiod sensitivity is an important trait related to crop adaptation and ecological breeding in common buckwheat (Fagopyrum esculentum Moench). Although photoperiod sensitivity in this species is thought to be controlled by quantitative trait loci (QTLs), no genes or regions related to photoperiod sensitivity had been identified until now. Here, we identified QTLs controlling photoperiod sensitivity by QTL analysis in a segregating F₄ population (n = 100) derived from a cross of two autogamous lines, 02AL113(Kyukei SC2)LH.self and C0408-0 RP. The F₄ progenies were genotyped with three markers for photoperiod-sensitivity candidate genes, which were identified based on homology to photoperiod-sensitivity genes in Arabidopsis and 76 expressed sequence tag markers. Among the three photoperiod-sensitivity candidate genes (FeCCA1, FeELF3 and FeCOL3) identified in common buckwheat, FeELF3 was associated with photoperiod sensitivity. Two EST regions, Fest_L0606_4 and Fest_L0337_6, were associated with photoperiod sensitivity and explained 20.0% and 14.2% of the phenotypic variation, respectively. For both EST regions, the allele from 02AL113(Kyukei SC2)LH.self led to early flowering. An epistatic interaction was also confirmed between Fest_L0606_4 and Fest_L0337_6. These results demonstrate that photoperiod sensitivity in common buckwheat is controlled by a pathway consisting of photoperiod-sensitivity candidate genes as well as multiple gene action.