杂交玉米花期预测及调控途径的研究

根据玉米杂交制种和科研实践,研究分析了玉米杂交制种过程中多导致花期不遇的因素,提出玉米花期预测的叶片观察法、幼穗分化观察法、叶脉预测、未生长出叶预测和叶环预测等方法。同时,针对父母本花期不遇时给出错期试验、苗期、拔节孕穗期、抽雄开花期的调控措施和补救措施。对指导玉米制种生产和提高制种量具有重要意义。     

浅谈杂交玉米制种花期预测与调节

杂交玉米制种产量高低的关键在花期是否相遇，而花期相遇的关键在于及早预测和调节。因此，及早做好制种玉米的花期预测及调节十分重要。1花期预测杂交玉米花期预测的方法很多，笔者经实践观测，认为最准确的有以下两种：1.1叶片检查法在玉米拔节后检查母本和父本的叶片数，如果两个亲本的总叶片数相同，而母本已出叶片数比父本多1~2片时，花期才能良好相遇。如双亲的总叶片数不同，或者双亲的总叶片数不确定，则应根据父本和母本已出叶片数、出叶速度和未出叶片数而定。如母本未出叶片数保持比父本少1~2片叶时，则花期相遇良好；如超过2片…     

杂交玉米制种的花期预测和调节

玉米杂交制种父母本花期能否相遇是制种成败的关键,也是决定制种产量和质量的重要因素.但是由于气候、种子活力、栽培管理等问题,常常导致花期相遇差,制种产量低,直接影响了经济效益和社会效益.因此,在杂交玉米制种过程中,应经常检查芽、苗、叶龄等来预测花期相遇情况,并及早采取相应调控措施,以确保花期良好相遇.     

影响玉米制种的气象条件

在玉米杂交制种过程中，影响产量的因素很多，其中大家担心最多的是玉米杂交制种的花期调节。在制种过程中，父母本花期相遇不好是造成产量低、成本高的直接原因。笔者也曾探讨过花期调节技术，对玉米杂交制种也有很大的帮助，但后来在实践中发现，要想更好的解决玉米制种过程中父母本的花期相遇问题，还必须对制种地区的气象条件有一个深刻的了解，这样才能更好地发挥花期调节技术。     

玉米制种花期预测与调控二十法

玉米制种花期能否相遇是制种成败的关键，也是决定制种产量和质量的重要因素，本文就玉米花期进行了相关的试验、研究与分析，根据玉米生长发育速度、幼穗分化进程等进行了科学预测，并对花期相通差的玉米通过栽、管、割、化、摸、剪、辅等相应的技术措施进行调控，科学总结出二十条预测、调控花期新技术，为今后玉米制种确保花期如期相通提供了技术保障。     

杂交水稻制种花期预测及调节

杂交水稻制种产量高低的关键在于花期是否相遇 ,而花期相遇的关键除了准确安排播种错期外 ,最重要的是及早预测和调节花期。因此 ,及早做好制种田的花期预测及调节十分重要。1　花期预测杂交水稻制种花期预测的方法很多 ,笔者经多年的观测 ,认为最准确的有以下两种方法 :1.1　双零叶观测法。所谓双零叶是指两叶叶枕重叠。第一双零叶也称假双零叶 ,出现在水稻移栽后 ,指移栽后长出的第一叶与倒二叶叶枕重叠的现象。第二双零叶即真双零叶 ,是指在幼穗分化前后出现的倒五叶与倒四叶 (剑叶是倒一叶 )叶枕重叠的现象。这是水稻由营养生长转入生殖…     

杂交玉米制种产量不高的原因与防范措施

杂交玉米制种花期相遇与否直接影响杂交制种产量,影响种子生产者、经营者的经济效益,更重要的是影响来年玉米生产。正确分析花期不遇原因、采取相应的预测和调节措施,是种子生产技术人员的首要任务,是提高杂交制种玉米产量的有效途径。     

叶环在玉米制种和花期预测中的重要作用

1叶环的概念玉米的叶由叶片、叶鞘和叶舌三部分组成。这里所说的“叶环”，是指在叶舌的着生部位、在叶的背面叶与叶鞘相连接的环状结构。它在外部形态上是区别展开叶与未完全展开叶的重要标志，展开叶（100%展开）在叶基背面可以看到环状结构即叶环，未完全展开叶在叶基背面看不到环状结构。一般展开叶与未完全展开叶应以该叶的叶环是否从下面相邻展开叶的叶鞘中露出为依据。2叶环在花期预测中的重要作用能否正确预测花期和调节花期是玉米制种成败的关键，对新引进的制种组合更为重要。而在花期预测中无论是叶片检查法、剥叶检查法、镜检雄…     

杂交玉米制种的播期调整与花期预测方法

杂交玉米制种因父母本花期长短不同,播种时要进行播期调整,并在苗期及时搞好花期预测。然而制种者多忽略因特殊气候因素的变化与自交系本身习性的关系而发生的生理指标变化,只注重数量指标,导致虽然正常调整播期,仍然出现花期不遇的现象。下面就杂交玉米制中播期调整与花期预测的方法及注意事项谈谈自己的看法,供参考。     

粳型杂交稻制种中父母本花期调节的几项措施

粳型杂交水稻制种中父母本花期调节，根据水稻幼穗分化进程，预测父母本花期，采取对肥料，水浆，割叶，喷赤霉素等措施调节父母本花期相遇。     

抽穗开花期不同高温处理对水稻开花习性和结实率的影响

为了探明高温胁迫对水稻的伤害机理,利用人工气候箱在水稻抽穗开花期对2个耐热性不同早稻品种进行不同高温处理,研究高温胁迫对水稻开花习性和结实率的影响。结果表明,随着胁迫温度的升高,日开花数减少,日开花峰值降低,开颖角度减小,花粉粒直径增大,花药开裂、花粉活力、柱头活力下降,结实率降低。相关分析表明,2个品种的结实率与花粉活力、花药开裂系数、柱头活力之间均呈显著正相关（R=0.9733*,0.9768*和0.9270*）。水稻抽穗开花期受高温的危害存在品种间差异,相同高温胁迫下,耐热品种996受高温的伤害小于热敏感品种4628。     

籼稻光温敏核不育系开花习性研究

摘 要：旨在为两系不育系高产制种提供理论依据。用‘广占63-4s’作对照,在相同时段内测定不育系的开花习性（开花历期、单穗逐日开花动态、花时分布动态、柱头特性、包颈率和张颖特性等.）‘F168s’单穗和单株开花历期均最长;‘信丰9826s’和‘信矮10-4s’比对照花期集中,盛花期累计开花率高,开花峰值高;除‘F168s’外,其余不育系集中开花时段开花率均高于对照;除‘信丰9826s’之外,其余不育系午前开花率均低于对照;‘F168s’柱头总外露率、柱头双外露率最高;‘信矮10-4s’柱头单外露率最高;‘F168s’柱头表面积和柱头体积最大,柱头活力系数最大,柱头活力最强;除‘信丰9826s’之外,其余不育系均有包颈现象;不育系张颖时间均超过对照,‘信矮10-4s’最长;除‘信丰9826s’之外,其余不育系的颖间距和张颖角度均超过对照,‘F168s’最大。不育系制种时采取扬长避短的制种技术和人工辅助措施,可提高杂交制种产量。     

成都市两系杂交水稻制种气候适宜性区划

为解决成都市两系杂交水稻就地制种难题,运用基于风险的气象诊断方法,笔者分析成都13 个区（市）县制种的3 个关键时期（两系不育系育性敏感期,亲本抽穗扬花期和种子成熟收获期）的安全性和适宜性,得到其两系杂交水稻制种适宜区域与时段。结果表明,多数分析时间段的抽穗扬花综合风险指数小于4.0,时长为44~95 天,为两系杂交水稻制种抽穗扬花安全期时段的选择提供了充裕的区间,因此制种基地适宜性主要由育性敏感期决定。在22.5℃阈值条件下,两系水稻最适制种区为金堂、龙泉驿、邛崃、蒲江、双流和新津;在23℃阈值条件下,两系水稻适宜制种区为新津、金堂、新都、大邑和双流;在23.5℃和24.0℃温度阈值条件下,成都适宜开展两系水稻制种的地区极少。如果在成都开展两系杂交水稻制种,应尽量选用不育起点温度低于23.0℃,并且育性敏感期时段较短的两系不育系,以减少制种纯度风险。     

北方粳型光温敏核不育系开花习性分析

为了提高北方粳型光温敏核不育系的实用价值及两系杂交粳稻的制种产量,以6个不育系为研究对象,对其开花习性进行研究分析。结果表明,不育系间开花习性差异明显,其中G 067 S单穗和单株开花期最短,LY 056 S的单穗和单株开花期最长;G 09 S、G 153 S、G 067 S、LY 056 S、LY 201 S花期和花时比较集中,G 178 S花期和花时都较为分散;G 153 S开闭颖时间最长,G 067 S最短;G 09 S开颖角度最大,G 178 S最小;G 067 S柱头外露率最高,LY 056 S柱头外露率最低;LY 056 S不包颈,其余不育系均存在不同程度的包颈。相关分析表明,不育系包颈与开闭颖时间和柱头外露间存在显著或极显著正相关,不育系颖花开颖角度与其他性状间相关不显著。     

油用牡丹花期预报

根据菏泽市2008—2019年油用牡丹花期观测资料及相应气象要素,利用滑动平均、相关分析及逐步回归等数理统计方法,分析了影响菏泽市油用牡丹始花期早晚的主要气象因子。结果表明：温度条件是影响油用牡丹始花期主要的气象因子之一,并与花期呈显著负相关;日照、降水及日较差等气象条件与油用牡丹始花期相关均不显著。选取2008—2018年对牡丹花期影响较大的气象因子,采用逐步回归方法,建立了油用牡丹始花期预报模型,可分别于3月21日、4月1日发布花期预报。模型历史回代（允许误差均在±1天）,并对2019、2020年进行试报,准确率均为100%,拟合程度较为理想,试报效果较好,满足气象服务需求。     

Synchronization of flowering in maize (Zea mays L.) by the genetic system pg11 pg12

Summary The mutant genotype pg11pg11 pg12pg12-epistasis of double recessive factors-determines greater precocity of flowering. The possibility of using this mutant in the production of hybrid seed as a mean of synchronizing flowering in parent strains of different earliness is studied. The differences between mutant and green control genotypes in the characters of days to pollen shedding, pollen production, and height of plants are evaluated. Four mutant lines are considered together with their respective green near-isolines in two distinct localities and across four successive plantings.The mutant near-isolines presented lower values than those of the green near-isolines for all the characters. The maximum reductions in days to flowring were obtained in early plantings and late maturity strains. The reduction in pollen production was about 50%. The reduced height of the mutants is explained, at least in part, by the correlation of this factor with days to flowering. The mutants did not prove to be more sensitive to the environment than their green near-isolines. Seed production was not studied since the mutant is very deficient for this character and it could therefore only be utilized as the male parent. We concluded that the mutant, could be used to synchronize flowering in the industrial production of hybrid seed.     

Patterns of variation in flowering and seed set of meadowfoam

Patterns of flowering and seed set were explored by principal component (PC) analysis of counts of fresh flowers, total flowers and seeds at four observation times. This pattern analysis was attempted because of the complicated rhythms of flowering and seed set over an extended period. The approach was considered superior to regressions (over time) for this data because of these pattern complexities, and because these were few time-nodes. Also it avoided the need to find optimum regression functions. Parsimony was achieved with a two-component ordination based on truncation at 70% of the total variance. The results for all characters showed that the first component concentrated on the middle period of flowering/seed set, and de-emphasized the early phase. The second component emphasized the extremities of the flowering/seed set span. The first component accounted for a large proportion of total variance (45.5% to 69.2%), which indicated its importance. The general meaning of the first component was ‘median flowering’, ‘general flower production’ and ‘median-to-late seed set’ for these characters fresh flowers, total flowers and seed set, respectively. The results showed that PC analysis successfully summarized the complex patterns of flowering/seed set and revealed the pattern differences between plants. It was apparent that no particular pattern of general flowering and seed set could be regarded as ‘typical’ in meadowfoam. It was confirmed that the population was diverse, this being typical of segregating plants within a randomly fertilized population. This revised version was published online in August 2006 with corrections to the Cover Date.     

Flowering, Pod Set and Reproductive Success in Soya Bean

Much of the variation in yield of soya bean [Glycine max (L.) Merrill] and other grain crops is associated with changes in the number of pods and seeds per unit area. Photosynthesis and seed characteristics are the primary determinants of pod and seed number, but recent research suggests that the temporal distribution of flower production may also play an important role. Soya bean has a long flowering period (up to 40 days or more), but most of the flowers are produced in a much shorter time. The length of the period varies among cultivars, growth habits (indeterminate and determinate) and environments. The reproductive success of flowers produced early in the period is usually greater than those produced later. Little is known, however, of the regulation of the temporal distribution of flower production or its potential role in determining pod and seed number at maturity. Research is needed to determine first, if the temporal distribution can be manipulated to increase pod and seed set and secondly, if such increases would result in higher yields.     

棉花花铃期土壤持续干旱胁迫对产量形成的调节效应

 通过花铃期不同持续时间土壤干旱处理,研究干旱胁迫对棉花产量形成的影响。表明持续干旱对子棉产量影响以单株成铃数＞成铃率＞单铃重。短期干旱胁迫W1处理增加成铃数显示子棉增产,同步抑制下部内围铃棉纤维和棉子的物质积累量,解除胁迫后形成盛花结铃阶段产量潜载优势,极显著提高下、中部外围和上部内围铃子棉产量,实现增产;花后持续20 d以上干旱胁迫效应会延续至花后50 d,整体降低各部位棉铃的积累物质供应量,产量器官虽具干物质积累相对优势,但子棉产量潜载势降低,单株成铃数、单铃重趋降显示子棉减产;干旱胁迫对子棉产量的调控显示区位效应,降产效应随干旱延长显示由下而上、由内而外区位拓展态势,解除胁迫可获得一定产量补偿。     

早熟高产玉米单交种生育特性与产量构成的关系

早熟玉米单交种子粒产量低的主要原因是营养生长期短，形成的叶片少且面积小，光合产物供应不足，从而导致穗部性状的劣化和子粒产量的不稳定性。以早熟为前提子粒高产的育种途径，除配合力选育外，还可以通过提高叶片生长率来实现。通过试验研究提出，在高配合力前提下把具有潜在高灌浆速率的早熟自交系同一定的中晚熟自交系组配单交，不仅可使营养生长期显著延长，同化物供应改善，而且也可使灌浆期显著缩短，从而达到早熟高产的目的。