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排序方式: 共有298条查询结果,搜索用时 15 毫秒
1.
《中国油料作物学报(英文)》2021,6(2):66-73
High and stable yield is the main goal of soybean genetic improvement. In this study, association analysis was used to detect the quantitative trait loci (QTL) for the plant height, and soybean growth period using 182 SSR markers in the RIL population of 136 F4:8 lines, which developed from a cross between photoperiod-insensitive cultivar ‘Dongnong 47’ and photoperiod-sensitive variety PI317334–B. The results showed that 33 QTLs related to soybean growth period and plant height traits were detected by compound interval mapping, and were located on 12 linkage groups including N, C1, C2, J, D1a, B2, E, G, A2, O, L, I, with the contribution rate of 7.85–33.84%. These QTL loci and linkage markers related to soybean photoperiod sensitivity, would be helpful to identify key genes that control soybean photoperiod sensitivity, and provide an important basis for the breeding of new photoperiod-insensitive soybean varieties based on molecular design breeding. 相似文献
2.
《动物营养(英文)》2019,5(2):174-178
This paper reflects the results of a short experiment conducted in parallel with a larger trial which aimed to test the assumption that ‘consumption of feed by broiler chickens during periods of darkness is largely negligible’. To that effect, on d 31, feeders of birds raised under intermittent lighting (IL), i.e. 1 h of light [1L]:3 h of dark (3D):1L:3D:1L:3D:1L:3D:2L:6D, were weighed at the onset and at the end of each period of darkness (or scotoperiod). Moreover, in order to compare the feeding behavior of IL birds with that of broilers raised under continuous lighting (CL, i.e. 18L:6D), their feeders were weighed in parallel and at the same time points. On d 31, feed intake of IL birds during scotoperiods represented 45% of their 24 h feed intake. Both CL and IL birds presented anticipatory feed intake prior to the long nocturnal period of darkness (6D), as well as higher feed intake right at the onset of lighting at 06:00. Feed intake of CL birds during the 6D nocturnal scotoperiod was negligible at around 2% of their total feed intake. Intermittent lighting birds exhibited excitement at the start of each hour-length scotoperiod and, within that time, ingested around 2.5 times the amount of feed ingested by CL birds. Although short, this study revealed several interesting observations which might be worth further exploring in a larger, lengthier, behavior-focused experiment. Amongst other factors, it might be interesting to understand whether the high feed intake observed during scotoperiods for IL birds in reflective of the whole flock or rather a coping mechanism developed mainly by hierarchically lower-ranking birds to achieve their daily feed intakes requirements. 相似文献
3.
It was previously shown that nitrogen fertilization immediately after commencement of SD exposure enhanced the floral induction effect of SD in June-bearing strawberries (Sønsteby et al., 2009). In order to optimize the timing of such fertilization under field conditions, seasonal timing of floral initiation in the strawberry cultivars ‘Frida’, ‘Polka’, ‘Korona’ and Florence’ was studied in the field at five contrasting latitudinal and altitudinal geographic locations in Norway and, for comparison, under controlled environment conditions with 12 h photoperiod and temperatures ranging from 9 to 18 °C. Serial collections and dissections of crowns from the various locations revealed that floral initiation was successively delayed with increasing latitude and altitude of the location, and with decreasing temperature under controlled environment conditions. Both in the field and in the phytotron, floral initiation was earliest in ‘Frida’ closely followed by ‘Polka’ and in due course by ‘Korona’ and finally ‘Florence’ which was particularly slow to respond. Floral initiation in the phytotron was progressively advanced with increasing temperature and was optimal at 15–18 °C. Flowering time in the field was mainly determined by thermal relations in the spring and early summer, and accordingly, it was strongly delayed with increasing latitude and altitude of the location. In addition, late floral initiation in autumn also delayed flowering in the spring. Based on these observations, optimal timing of autumn fertilization for the various locations and cultivars are suggested. 相似文献
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Oilseed rape yield potential could be improved lengthening the duration of the late reproductive phase by increasing the number of grains per unit area. Photoperiod sensitivity could be used as a tool to manipulate the reproductive phase and thereby the number of grains. The aim of this study was to assess (i) the effects of different combinations of photoperiod on the duration of different phases and (ii) analyze how the changes in that duration affect yield (and its components) as well as oil seed content in oilseed rape. Field experiments were conducted in a factorial combination of three cultivars and three photoperiod regimes: natural photoperiod (NP) which represents the control and extended photoperiod of 6 h over NP (NP + 6) during emergence (E)-flower buds visible (FBV) and FBV-maturity (M) arranged in a randomized complete block design with three replicates, during two years representing three environments. Results showed that oilseed rape evidenced photoperiod responses during vegetative and early reproductive phases. Due to the lack of correlation between the duration of the vegetative and reproductive phases, it is possible to speculate the vegetative period may be altered independently of the modification of the rest of the phases. The positive relationship between grain number per m2 and the duration of the late reproductive phase suggests that yield could be increased by lengthening the duration of that phase. Thus, regardless of the effect on the previous phase, the photoperiod sensitivity found in the early reproductive phase opens the possibility to manipulate the relative durations of vegetative and reproductive phases. Therefore, the length of the reproductive phase will be increased at the expense of a reduction in the duration of the vegetative phase, but without changing the whole duration of the crop cycle. This strategy could increase yield in oilseed rape in the future. Variations in yield were mostly explained by changes in the grain number per unit area without significant correlation with grain weight. However, a negative relationship between grain weight and grain number was found, showing a slight counterbalance in yield, by decreasing the grain weight. Since oil concentration appeared to be a more conservative attribute, increases in crop yield through a higher grain number per unit area would be a suitable strategy for improving oil yield as no reductions in oil concentration can be expected. 相似文献
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8.
光照对美凤蝶滞育蛹发育的影响 总被引:1,自引:1,他引:0
[目的]为消除滞育对蝴蝶产业的不利影响。[方法]利用人工气候箱,对光周期与光脉冲对美凤蝶滞育蛹发育影响进行了研究。[结果]结果表明,20℃LD12:12时,滞育蛹第31天开始羽化,持续36d,平均历期46.9d;LD15:9时第37天开始羽化,持续22d,平均历期47.7d。25℃时,LD12:12开始羽化时间为第18天,持续23d,平均历期25.9d;LD15:9为第19d,持续14d,平均历期为26.4d。在25℃时,断光后间隔2h进行2h光脉冲处理,羽化推迟4d,在第19天开始羽化,平均历期延长1.2d,为21.8d;断光4h后进行2h光脉冲处理,羽化提早2d,第15天开始羽化,平均历期缩短1.9d,为18.8d。[结论]光周期和光脉冲对滞育蛹发育均有一定影响,但影响不显著。 相似文献
9.
Salvatore Luciano Cosentino Giorgio TestaDanilo Scordia Venera Copani 《Industrial Crops and Products》2012,37(1):20-33
Fibre hemp can be grown under a wide range of agro-ecological conditions, but it requires special attention for several physiological features and crop management. A management strategy in order to reduce inputs and thus achieve acceptable yield could be achieved optimizing sowing time. With this respect, the effects of sowing date on hemp biology and yield was studied, using two monoecious and two dioecious genotypes. Field experiments were carried out in two subsequent years (2003-2004) in South of Italy, using drip irrigation system. Sowing time, in the two year period, ranged between March 10th and July 22nd. Optimal sowing time was observed between the end of April and the first three weeks of May; in that range, the dioecious Fibranova yielded the most in terms of aboveground biomass and stem dry yield, followed by Tiborszallasi, while the two monoecious showed the lowest yield. On the contrary, before and after that period, the shorter day length caused an early floral induction that strongly reduced stem and fibre elongation, and thus aboveground dry biomass and consequently stem yields. Based on this study a simulation model focusing on flowering prediction in Mediterranean environment was developed. 相似文献
10.
为揭示光敏色素如何响应外界环境及作用机理,并探讨其与苜蓿(Medicago)秋眠性的关系,以田间自然生长条件下的不同秋眠类型紫花苜蓿标准对照品种Norseman(FD1), Archer(FD5)和CUF101(FD9)为材料,应用RT-PCR测定在6月、8月、9月、11月采集的叶片PHYA和PHYB mRNA含量。结果表明:从6 月到11月,随着光照时间的逐渐缩短和温度的降低,3个不同秋眠类型紫花苜蓿品种PHYA和PHYB的mRNA含量均呈上升趋势,且PHYA mRNA含量比PHYB mRNA的含量高;除了6月份,其他月份均是随着紫花苜蓿秋眠性的提高,PHYA和PHYB mRNA表达呈上调趋势,且不同秋眠类型间的差距越来越大。据此推测PHYA和PHYB在苜蓿响应外界环境改变过程中起一定的作用,二者基因的转录受光周期与温度因子的调控,且随着光周期的缩短与温度的降低其mRNA量升高,PHYA和PHYB很可能参与了光周期与温度对紫花苜蓿秋眠性的调控。 相似文献