四季蜜龙眼夏季开花坐果特性及传粉昆虫种类调查

为了解四季蜜龙眼夏季开花坐果特性和传粉昆虫种类,于夏季开花期间选定花穗记录雌雄花和果实数量,并以随机网捕方式采集传粉昆虫进行鉴定。结果表明:四季蜜龙眼夏季花期平均每穗开花天数为12.9天,雌雄花比例为1:6.57,授粉受精期的温度处于25～36℃之间,在较高的温度条件下雌花坐果率达到27.6%;雌花脱落占雌花数的11.1%,小果脱落占雌花数的61.3%。传粉昆虫有5目13科21种,以花金龟科的种类最多,占总数的33.3%;其次为蜂类和蝇类昆虫,分别占总数的30.1%和24.1%。     

优质粳型新质源不育系的开花习性初步观察

对粳型新质源不育系抽穗、开花习性进行初步研究。结果表明：该不育系抽穗和开花较集中、高峰期较明显，始花3～4天后进入盛花期，每日11：30～12：30为盛花时；开颖时间长、开颖角度大、柱头生活力强。新质源不育系具有较好的开花习性。     

种子发育期收获的完整和发芽温度差异

从开花后10天到开花后70天每隔5天收获一次粳稻种子，用这些种子来调查了培养温度对完整和脱壳种子发芽的影响。以30℃培养时，开花后25天收获的完整种子的发芽％超过了脱壳种子的；并且在开花后65天以前各次收获的完整种子的发芽％均超过了其脱壳种子的。开花后不同时期收获的全部完整种子在20℃培养时的发芽％低于在30℃培养时的发芽％。完整种子和脱壳种子在20℃培养时的发芽％是相类似的。     

水稻新育成不育系开花习性观察

为了掌握源A5、源A10的开花习性与异交结实率的关系,使其更好地应用于三系杂交水稻的种子生产,于2010年3～6月在广西农业职业技术学院实习农场对源A5、源A10珍汕97 A、金23 A的开花习性进行观察试验.结果表明,在当年南宁的自然条件下,源A5整体开花历期为14 d,单穗开花历期为6d,第2天进入盛花期,占开花数的30.71％,开花时间为08:00～14:00,开花高峰期出现在12:00,闭颖开花率占47.7％,柱头外露率为66.9％,颖壳张开度29.1°;源A10整体开花历期为14d,单穗开花历期为6d,同在第2天进入盛花期,占开花数的33.79％,开花时间为08:00～14:00,开花高峰期出现在12:00,闭颖开花率占49.2％,柱头外露率为72.9％,颖壳张开度30.3°.珍汕A整体开花历期为15 d,金A整体开花历期为17d,单穗开花历期同为7d,开花盛期均出现在第4天,开花时间分别为09:00～13:00、08:00～ 14:00,开花高峰期分别为11:30、11:00,闭颖开花率分别占30.2％和35.4％,柱头外露率分别为46.7％和77.3％,颖壳张开度为26.4°和25.6°.     

甘蔗早花亲本断夜处理效果研究

探讨断夜处理对延迟甘蔗早花亲本开花的效果,于2006、2007和2008年分别进行不同光照强度的断夜处理试验。结果表明,参试品系CP85-1491和HoCP93-746在L3、L4处理下及其他品系在各处理下的花期在杂交授粉期间,抽穗率、始花期、延迟开花天数和开花高峰期等各考察指标均适合杂交制种需要;各年份下,随着光照强度的增强,各参试材料的始花期和延迟开花天数逐渐增加,开花高峰期逐渐推迟,抽穗率也随之下降;相同年份下各处理,不同参试材料的始花期、延迟开花天数和抽穗率差异较大,随着光照强度的增强,同一参试材料的始花期、延迟开花天数、终花期和抽穗率年份间差异有逐渐加大的趋势;而开花持续期平均约1个月左右,并不受光照强度的影响。多数早花亲本在10.5~105 lx的光照强度范围易得到较好的延迟开花效果,该研究为目前甘蔗种质创新和杂交花穗生产提供技术支持和理论依据。     

36种常用栽培药材种子播种质量现状研究

从待售种子批中取样，以检测其净度、生活力和千粒重，定量了解我国常用栽培药材种子播种质量现状。结果表明，来自不同市场或产区的药材种子质量参差不齐，36种药材770批次种子的净度平均为90．5％；生活力平均为54％，16．2％的种子批生活力低于20％；净度及生活力均达播种要求的种子批仅占52．6％；同种药材不同批次种子生活力、千粒重均存在较大差异，RSD分别达58．71％、14．38％。总体而言，种子播种质量较差，亟待改善。     

大豆花荚脱落特性的研究——贵阳地区大豆花脱落习性的观察

本文对14个大豆品种在单、间作条件下进行了花荚脱落习性的观察,结果表明:1.大豆花荚脱落的顺序和开花习性是一致的,开花早的花朵,脱落早,同一品种,单作的花荚脱落比间作早。花朵开放早的部位,脱落也早,主茎花荚脱落早,分枝花荚脱落较晚。2.落花落荚在整个开花结荚期都能发生,花荚脱落的高峰期多出现在末花至结荚期,有限结荚习性品种出现得早,亚有限结荚习性品种则较晚,同一品种单作比间作出现得早,处于不良的环境条件下可能会出现几个高峰期。3.花荚脱落的部位与大豆始花部位的商低有关,始花早,始花部位越低;始花越晚,则始花部位越高;开花早的部位,花朵数多,落花数也较多,但成荚数也多;开花晚的部位,则反之。同品种间作比单作最早出现花荚脱落的节位高1～2个节位;分枝上的花荚脱落大于主茎。4.单株开花数、花开天数、结荚天数与花、荚脱落率呈正相关,成荚数与花、荚脱落率呈负相关。5.耐阴品种的花荚脱落率低于不耐阴品种;除少数品种外,落荚率高于落花率;单作的落花率、落荚率和花荚脱落率除个别材料外,均低于间作,单、间作之间的t测验除落荚率接近显著水平外,落花率与花荚脱落率达到了显著水平。大豆花荚脱落是普遍而严重的,单作大豆一般花荚脱落率为50～60％;严重的可达70～80％。贵州,大豆种植多是间套作,尤以玉米、大豆间作为多,间作大豆的花荚脱落率未见详细报道。为探讨在贵州的生态、栽培气候条件下,特别是间作大豆花荚脱落的习性,我们开展了大豆花荚脱落习性的观察,为贵州大豆增花保荚,减少脱落以及为提高杂交育种成功率提供理论依据。     

蔗糖对小黑麦离体培养穗粒数的调节作用

利用小黑麦植株穗的离体培养技术，研究了不同蔗糖浓度对穗粒形成的影响。结果表明：在开花前13天到开花1天。不同浓度的蔗糖供给对穗结实率有不同的影响，随着蔗糖浓度上升，总结实率增加，但蔗糖浓度超过4％，穗结实率开始下降。在0．0～0．5％蔗糖浓度下．上部节间仍有～定的生长。但生长缓慢．不能抽穗。为明确蔗糖对穗粒数的调控的最敏感时期，设置了开花前不同时期降低蔗糖浓度的试验。蔗糖浓度为0．5％和4％2个处理。处理为开花前13～9天、8～4天、3天～开花。结果表明：不论在何时段，用0．5％蔗糖浓度处理，均比正常蔗糖4％处理穗粒数减少，就下降而言开花前13天＞3天＞8天＞0天；穗粒数率最敏感的时期：一是在开花前13—9天，二是开花前3天～开花。     

杂交水稻两优培九强弱势粒结实生理研究

杂交水稻两优培九抽穗当天，强势粒（上部一次枝梗籽粒）中总RNA、mRNA含量都高于弱势粒（下部二次枝梗籽粒）。抽穗后第5天，强势粒中总RNA含量仍然高于弱势粒，mRNA含量两者差异不大。开花当天（强势粒抽穗当天，弱势粒抽穗后第7天）和开花后第5天（强势粒抽穗后第5天，弱势粒抽穗后第12天），强势粒中总RNA、mRNA含量和单     

普通野生稻抽穗特性的调查研究

普通野生稻南宁晚季平均始穗期在９月２９日或３０日，在不同年度间较稳定。在早季，普通野生稻的抽穗率和始穗期在不同年度间差异较大，抽穗率变化在２４．４％至６８．７％之间，始穗期差异４至１５天，一般早季较迟抽穗的类型晚季平均始穗期略早；遗传纯合性较高的群体早季抽穗率较低或不抽穗，其晚季始穗期也较趋于一致。植株形态为匍匐的类型晚季始穗期比倾斜、半直立和直立类型迟，来源于纬度较高地区的群体，其平均始穗期较早。     

Genetic variation in seed production and its components in four cultivars of the pasture grass Setaria sphacelata

Variation in seed production and its components was investigated between and within four cultivars of the pasture grass Setaria sphacelata, in two experiments over two years, as a basis for future cultivar improvement. The study sought to determine the basis for the considerable differences in seed production of the four cultivars Nandi, Narok, Solander and Kazungula, to determine the extent of genetic variation in the four cultivars in attributes which contribute to seed yield, and to investigate genotypic consistency in seed production over years and seasons. Each experiment comprised 50 genotypes of each cultivar. In the first experiment, plants were harvested a set number of days after median flowering date whereas in the second experiment, which was unreplicated, each genotype was harvested a set number of days after it had flowered. In the first experiment, seed yields were generally highest for Kazungula, lowest for Narok and intermediate for Nandi and Solander. All measured attributes contributing to seed yield exhibited a high order of variation between and within cultivars, but the basis for the large difference in seed yield per plant between cultivars was tiller fertility rather that total tiller number. Averaged over the four harvests, there was a six fold to > 100–fold intra-cultivar genetic range in seed production, associated with differences in tiller fertility, which were associated with differences in date of first flowering. Broad sense heritability for seed yield averaged 0.68 for the four cultivars and showed little change over the four harvests. Genotypes which produced high seed yields in summer were also more productive of seed in autumn and the 0ore productive genotypes in the first year were also more productive in the second year. Cultivars differed in the relative importance of factors which contributed to the high seed yield of high-yielding genotypes. In the second experiment, genotypes with a high seed yield also generally had the highest tiller fertility, even though all genotypes were harvested the same number of days after first flowering. Within-cultivar correlations in seed yield between the two experiments were generally significant and the elite 20% of genotypes from this experiment had 1.2–2.9 times the seed yield of the same genotypes with a very different harvesting regime in the first experiment. It is concluded that opportunities exist in all four cultivars for improvement in seed production and that the selection criterion offering the best opportunity for advance would be fertile tiller number. In Narok, Solander and Nandi, this would result in increased tiller fertility, whereas in Kazungula, it would result in an increase in total tiller number. This revised version was published online in July 2006 with corrections to the Cover Date.     

Path analysis of the relationships between seed yield and some morphological and phenological traits in safflower (Carthamus tinctorius L.)

Path analysis was performed on plant characters of six safflower genotypes grown in a two year field experiment to determine for seed yield, the direct and indirect effects of the following traits: total biomass, stem yield, number of primary branches/plant, number of secondary branches/plant, number of seeds/m², number of seeds/capitulum, number of capitula/plant, capitulum diameter, 1000-seed weight, seed weight/capitulum, distance between ground level and the first fertile branch, plant height, number of days to the beginning of branching, number of days to the beginning of flowering, number of days to 50% flowering, number of days to full flowering and flowering duration. Seed yield was significantly correlated with the following traits: total biomass, stem yield, capitulum diameter, 1000-seed weight, seed weight/capitulum, distance between ground level and the first fertile branch, number of days to the beginning of branching and flowering duration. Total biomass, seed weight/capitulum, distance between ground level and the first fertile branch, 1000-seed weight and flowering duration had substantial direct effects, in that order, on enhancement of seed yield. The significant positive correlation coefficient of capitulum diameter with seed yield resulted from positive indirect effects of total biomass, seed weight/capitulum and 1000-seed weight. Conversely, the significant negative correlations between number of days to the beginning of branching and distance between ground level and the first fertile branch and seed yield resulted from negative indirect effects of the same three traits. Stepwise multiple regression analysis showed that 94% of the total variation in seed yield could be explained by variation in total biomass and by number of days to the beginning of branching (84 and 10%, respectively). Results suggest that total biomass and number of days to the beginning of branching are primary selection criteria for improving seed yield in safflower.     

刈割时间对苜蓿生殖生长及种子性状的影响

试验以‘新牧4号’紫花苜蓿为材料,研究不同刈割时间对苜蓿生殖生长及种子特性的影响,以期为提高苜蓿种子产量提供基础数据。试验数据表明,刈割对苜蓿生殖格局、种子产量和种子特性等影响较大。其中,返青后第44（5月8日）、51天（5月15日）刈割,与对照相比,种子千粒重分别增加24.44%、30%,种子产量分别提高26.85%、45.86%,种子发芽率分别降低了2.12%、10.63%。刈割能够延迟苜蓿花期,通过改变苜蓿花期的外部环境和花的传粉效率来影响其结实特性。在苜蓿孕蕾至初花期间,适时刈割1次,能够提高花的传粉受精效率,降低生殖败育率,增加种子产量。     

桉树人工林土壤种子库研究

为了了解桉树人工林土壤种子库的物种组成、密度、垂直分布等特征,以2年生桉树人工林为研究对象,相邻的大叶栎人工林作对照,取其土壤,通过室内种子萌发的方法,研究桉树人工林土壤种子库分布特征。结果表明：（1）各土壤层种子萌发的规律基本一致,大约从第7天开始进入种子萌发高峰期,第19天萌发高峰期基本结束,随后进入缓慢萌发期,至最后停止萌发;（2）桉树人工林土壤种子库储量较大,种子密度为9804粒/m2（对照为3614粒/m2）,共计物种15种,分属于9科,其中禾本科的弓果黍为优势种,种子密度为8849粒/m2,占土壤种子库总量90.26%;（3）种子库垂直分布格局显示,80%以上的种子储存在枯枝落叶层和0~5 cm的土壤中。2年生桉树人工林土壤种子库的种子密度大于大叶栎人工林,其组成以草本为主,灌木次之,种子多集中在枯枝落叶层和浅层土壤中。     

扁穗雀麦种子成熟过程生理响应及适宜收获期研究

为探究扁穗雀麦种子成熟过程中的生理响应,明确适宜的收获条件和时间,以扁穗雀麦"江夏"和"黔南"为试验材料,对种子成熟过程中含水量、粒重、贮藏物质、酶活性和ATP进行研究.结果表明,随着种子的成熟,含水量呈持续下降趋势,但最大失水率在品种间有较大差异."江夏"在花后第33～38天失水率最高,每天为4.94％,而"黔南"在...     

绥宁县超级杂交稻制种气候风险分析

为明晰绥宁县超级杂交稻制种气候风险,利用1:250000地形数据和40年气候资料,根据杂交稻制种的气候风险等级指标,分析了绥宁县杂交稻制种过程中的气候风险;并运用地理信息系统的空间分析方法,对绥宁县杂交稻制种气候风险进行了细网格推算分析。结果表明：不育临界温度23.0℃时育性敏感期风险最低时段为7月11—31日,气候风险2.5%;23.5℃时为7月11—31日,气候风险5%。绥宁县扬花天气综合危害指数6—8月较低在2.5以下,将扬花期安排在9月14日之前可获得较高制种产量。不育临界温度22.0℃时无风险制种区分布于中南部沅水支流河谷沿岸平原地区;22.5、23℃时较安全制种区分布于中南部河谷及东北端的红岩等乡镇;23.5℃时全县大部为制种高风险区域。对播种至始穗期为80天的不育系,不育临界温度22.0℃时将播种日期安排在5月4日或25日,22.5℃、23℃时将播种日期安排在5月4日,既可获得较高制种产量,又可使不育系育性转换的气候风险处于最低值。     

开花期气象因子对油菜结实的影响

基于2011—2018年油菜开花日挂牌标记试验,考种不同开花时段油菜结荚率、单荚子粒数,分析不同时期低温对油菜结实的影响,建立气象因子与油菜子粒损失率的影响定量关系。结果表明,2月25日前的低温对油菜结实的影响以中度和重度为主,3月中下旬的低温对油菜结实的影响以轻度为主,2月26日—3月10日的低温对油菜结实的影响以轻度和中度为主。油菜子粒损失率与开花时日最低气温平均值、日平均降雨量相关不显著,与开花时平均气温、日最高气温平均值、日照时数平均值、日平均相对湿度相关显著。随开花平均气温下降,日最高气温平均值下降,空气相对湿度升高。开花时空气相对湿度为70%,且日平均气温≤6.9℃,或空气相对湿度为80%,日平均气温≤8.0℃,油菜中度受害;开花时空气相对湿度为80%,且日平均气温≤4.3℃,或空气相对湿度为85%,日平均气温≤4.8℃,油菜重度受害。其次分析确定了不同天气类型下油菜开花结实的冷积温指标,当日照低温天气的冷积温指标为≥16.5℃,或无日照低温阴雨天气的冷积温指标为≥5.0℃,为中度受害。当日照低温天气的冷积温指标为≥37.5℃,或无日照低温阴雨天气的冷积温指标为≥26.0℃,为重度受害。试验结果可为油菜灾害预警评估和减灾防灾农业气象服务提供技术支撑。     

花期弱光持续时间对玉米果穗发育及产量的影响

为探明花期连阴雨造成的弱光胁迫持续时间对玉米产量的影响,以黄淮海平原主推夏玉米品种浚单29为材料,自抽雄期起设置弱光胁迫处理0 d(CK)、3 d(S3)、6 d(S6)、9 d(S9)、12 d(S12)、15 d(S15)6个处理,探讨了玉米花期弱光持续时间对玉米果穗发育及产量的影响。结果表明,自抽雄期起,随着弱光胁迫时间的延长,弱光处理3~15 d,吐丝期较CK推迟1~7 d,终散粉日较CK推迟1~2 d。在抽穗后第11天所有处理散粉全部结束。散粉100%结束日吐丝株率较CK减少3%~43%,各处理结束日果穗长度的增长速率和雌穗干质量增长速率分别较CK降低71%~79%和83%~100%,但对最终的苞叶长度无显著影响。弱光处理3~15 d,导致受精率和结实率较CK分别降低22~58,16~71个百分点(P0.05)。抽雄期起3~15 d的弱光胁迫显著降低了植株干物质积累速率,恢复自然光照后,干物质积累速率呈现恢复性增长,但仍低于CK。随着弱光胁迫持续时间的延长,成熟期果穗长度、结实长度显著降低,秃尖长度显著增加,穗粒数和籽粒产量显著降低(P0.05),百粒质量无显著变化。