Nectar secretion of RN-type cytoplasmic male sterility three lines in soybean [Glycine max (L.) Merr.]

1. Introduction

Soybean is one of the most important oil crops and is the main vegetable protein source in the world. However, the yield per hectare and the genetic gain per year are lower than those of other major field crops. Use of heterosis is an effective approach to improve crop yield. Chinese scientists were the pioneers for use of heterosis in soybean and have been successful in recent years. The first soybean cytoplasmic male sterile (CMS) line and its maintainer were reported in 1993. The sterile cytoplasm came from the landrace Ru Nan Tian E Dan, which was designated as RN cytoplasm (Sun et al. 1993, 1997, 2001, 2003). Four more origins of sterile cytoplasm from China were reported later (Zhang and Dai 1997; Gai et al. 1999; Zhao and Gai 2006; Nie et al. 2017). Based on RN CMS System, the first hybrid “HybSoy1” was released in China in 2002 (Zhao et al.2004). This hybrid yielded 21.9% more than control cultivar in two-year uniform test. Several hybrids were released later on. However, the extensive application of these hybrids in production is still limited due to the low seed setting of female parent in seed production, resulting in prices for hybrid seeds quite higher and negatively affecting farmers’ incomes.

Soybean flowers possess anatomical adaptation characteristics of entomophilous plant species (Palmer et al. 2001). Soybean is a typical self-pollinated crop, and cultivated soybean has a natural out-crossing rate of around 0.03 to 6.32% (Caviness 1966; Carlson and Lersten 1987;Sun et al. 1992; Ahrent and Caviness 1994; Jeffery 2003).Successful production of hybrid seeds requires efficient pollen transfer from male to female plants. Insects such as honeybees and leaf cutting bees were reported to be good pollen vectors (Ortiz-Perez et al. 2008; Zhao et al. 2009).There is a wide range of variation of out-crossing rate among nuclear male-sterile and CMS lines and significant preferential attraction of pollinators occurred in both open fields and caged plot conditions (Graybosch and Palmer 1988; Ortiz-Perez et al. 2006a, b, 2008; Zhao et al. 2009). In addition to morphological characters such as number, size, color and openness of flowers, the quantity and quality of rewards including nectar, pollen grains, and volatile matter may play an important role in this preferential attraction (Erickson 1975,1983, 1984a). A parallel trend was found between insect number and amount of flower nectar in a day with a peak time from 12:00–13:00 in Taiyuan of China, suggesting that soybean nectar attracts insects (Dai et al. 2017). Erickson(1984b) proposed that soybean secreted nectar, and great variation of quantity (0 to 0.8 μL) and quality was found among different genotypes. Horner et al. (2003) described the fine structure of floral nectaries and development in soybean.Three stages of nectary development- preactive, active,and postactive - were identified within 24 hours. The first two stages occurred when soybean flowers did not open.Three major components of soybean aroma were identified and the production of those components varied during the day, to signal different situations of nectar secretion. However,those components were not specified by the chemical names(Robacker at al. 1988). Jaycox (1970) noted the preferential attraction and pointed out that the size of bee population visiting soybean field could be an indicator of attractiveness of different soybean varieties. For example, more bees were observed in the plot of variety “Wayne” than that of“Harosoy”. The seed-setting rate of CMS lines varied greatly among genotypes from less than 10% to over 100%, and also changed in different environments (Dai et al. 2017). This means that the seed-setting rate of CMS A-lines is an indicator of success of pollen transfer and preferential attractiveness.

2009年 全国人大常委会食品安全法执法检查组第一次全体会议在北京人民大会堂举行，标志着食品安全法执法检查正式启动。

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However, the biology of attractiveness of different genotypes to the pollinator and environmental factors involved have not been investigated. This paper addressed the secretion of nectar from CMS A-, B-, and R-lines with different seed-setting rates and the rhythm of nectar production.

2. Materials and methods

2.1. Plant materials

Nectar secretion of restorers JLCMS118R was examined for three consecutive days (July 12–14, 2007) to evaluate consistency of the nectar secretion rhythm (Fig. 1). The weather in those three days was sunny with relatively high temperatures. The nectar secretion pattern was highly consistent over these three days even though the starting time of nectar secretion varied slightly. The nectar secretion started at 07:00 on July 12, at 06:00 on July 13, and at 06:30 on July 14. Secretion ended at 17:00 on all three days. The nectar secretion peak occurred at 08:00–08:30. A sub-peak was found at 13:00 on July 13 and July 14, and at 14:00 on July 12. It was obvious that better weather one or two days before the samples were taken played an active role in nectary development and nectar secretion. Peak secretion time occurred soon after the initiation of nectar secretion and decreased very fast on July 12, and there was an obvious sharp peak compared to the other two days.

2.2. Design of field experiments

The present study also found that R-lines had higher nectar production compared to A- and B-lines. One of the possible reasons might be the less diversified origin of R-lines. The restoration sources used in our breeding program mainly came from a foreign country while the maintainers primarily came from domestic genetic resources. There is a possibility that different selections in foreign breeding programs unconsciously favored the performance of nectar secretion or that varieties with higher nectar production were used as the basic genetic background in foreign breeding.

Clearly continuous high temperature and lower rainfall are important for improving nectar secretion and maintaining a high out-crossing rate. This information provides a guidelinefor the selection of hybrid seed production regions. In areas where there is less rainfall and higher temperatures,especially enough high daily average temperatures during the whole flowering period, these sites will be the ideal places for hybrid seed production. However, great differences of seed setting rate of CMS female parents exist at the same place because of preferential visitation by pollinators. Female and male parents should be balanced in regard to attractiveness to pollinators, because nectar and pollen grains are rewards for pollinators. Sterile pollen grains in CMS lines are not as attractive to pollinators and more nectar production in CMS lines is required to maintain attractiveness to pollinators. The present study showed that the yield of hybrid seeds in female parent JLCMS9A of HybSoy1 was relatively low, and the nectar production of JLCMS9A was only one third of male parent JLCMSR1. It is possible that pollinators visit male parents continuously for both nectar and pollen grains and seldom visit female parents. This leads to a low seed setting rate in female parents since pollination is only achieved when pollinators alternate between visits to male and female plants. Higher nectar production in both female and male parents is better than unbalanced nectar production between male and female parents; however, more studies needs to be done to verify this assumption.

Stage 1: The rhythm of diurnal nectar secretion was analyzed using restorers JLCMSR118 in the summer of 2007 for three consecutive days. Nectar secretion rhythm was analyzed based on six genotypes to detect differences in diurnal variation of nectar secretion. Nectar secretion of 12 genotypes at peak secretion time was analyzed over 10 consecutive days to observe the relationship between nectar secretion and weather conditions in 2007.

Stage 2: A total of 27 CMS soybean lines including nine A-lines, nine B-lines, and nine R-lines were used to study the difference of nectar secretion among genotypes. At the same time, the out-crossing rate of nine CMS A-lines was determined.

总体球化思路是选择纯净的原铁液，采用低稀土球化剂，利用冲入法先球化后孕育的方式，待球化进行时孕育剂采用孕育工装进行孕育，浇注时再进行一次随流孕育。球化剂及孕育剂的加入量及成分见表1。

2.3. Methods of sampling nectar

Out-crossing rate (%)=Average pod number per plant for a CMS A line/Average pod number per plant for its maintainer B line×100

2.4. Evaluation of out-crossing rate

Nine pairs of A- and B-lines were planted in the row radio of 1:1 for evaluating the out-crossing rate of male sterile A-lines in the cages. The size and cover of the cage were the same as mentioned above. Row spacing was 60 cm with 8 cm between plants within a row. At the beginning of the R1 (begining bloom) period (Fehr et al. 1971), honeybee hives were moved to the cages, and about 500 honeybees from each hive were used to pollinate. At the R6 (full seed)stage, 10 plants from each of A- and B-lines were sampled randomly to count pod setting. Plants near the edges of the cage were not selected. Then out-crossing rate was calculated using the following formula:

Nectar was sampled from flowers using a 1-μL capillary(manufactured by Drummond Scientific Company, USA).The nectar within each replication was collected starting with the first line, then the last line, and finally in the reverse direction to avoid artificial error. Nectar was sampled from 10 flowers in five plants with three replications. The selected flowers were chosen from the middle of the plants.Because there was no scale on the capillary, a ruler with minimum of 0.1 mm scale was used to measure the length of the nectar in the capillary. A 30× magnifier was also used to help reading scale and 0.05 mm was recorded by estimation. The inner diameter of capillary is 0.0079 inch.The length was then converted to the reading of microliter.Here 0.1 mm on the ruler equals to 0.003125 μL. To reveal the diurnal rhythm of nectar secretion, samples were taken every 30 min from 06:00 to 17:00. The samples in other experiments were collected between 07:00–08:30 during the peak of nectar secretion.

2.5. Data analysis

SPSS 19.0 (IBM Corp. Released 2010. IBM SPSS Statistics for Windows, version 19.0, Armonk, NY, USA) was used for all analyses. Analysis of variance (ANOVA) for out-crossing rate and nectar secretion of different genotypes from three lines, means between genotypes, and years and types were compared based on the least significant difference (LSD)test at 0.05 probability level. Correlations between nectar secretion and meteorological factors, nectar production of CMS A-lines, nectar production of CMS B-lines, and outcrossing rate of CMS A-lines were also analyzed.

3. Results

3.1. Diurnal nectar secretion rhythm

A total of 27 CMS soybean three lines were randomly selected among 463 available three lines. Nine CMS lines(A-lines): JLCMS29A, JLCMS101A, JLCMS8A, JLCMS82A,JLCMS14A, JLCMS47A, JLCMS9A, JLCMS31A, and JLCMS89A; nine corresponding maintainers (B-lines):JLCMS29B, JLCMS101B, JLCMS8B, JLCMS82B,JLCMS14B, JLCMS47B, JLCMS9B, JLCMS31B, and JLCMS89B; and nine restorers (R-lines): JLCMSR1,JLCMSR2, JLCMSR4, JLCMSR14, JLCMSR26, JLCMSR33,JLCMSR50, JLCMSR75, and JLCMSR118. All materials were developed by the Soybean Research Institute, Jilin Academy of Agricultural Sciences, China.

要出差，早上出门我对女儿说：宝贝，来吧，亲亲爸爸。女儿不搭理我，于是我再次恳求她。妻子也劝，“宝贝，爸爸今天要出差了，你亲亲他嘛。”我也继续恳求“来嘛来嘛，宝贝，亲亲爸爸。”终于女儿不太情愿地亲了我一下。然后对她妈妈说了句不耐烦的话：“你老公还真娇气。”

3.2. The effect of meteorological factors on nectar secretion

Fig. 1 Nectar secretion of JLCMS118R for three consecutive days (July 12–14, 2007).

Fig. 2 Nectar secretion of six genotypes from 06:30 to 17:00(2007).

Nectar from six genotypes was collected at peak secretion time daily from July 15 to July 24 in 2007. The sampling time was postponed to 09:00–09:30 instead of 08:00–08:30 on July 18 because of rainy weather (Table 1). Fig. 3 shows that the nectar quantity increased from July 15 and reached the highest level on July 17. Almost not any nectar was collected on July 19 and the secretion activity recovered gradually by July 20. However the nectar secretion remained at lower level over the next six days. This agreed with Erickson’s (1984a) study that soybean plants did not secrete nectar during cool weather and required three days to recover the ability to produce nectar even though subsequent flowers were open each day. It was clear that the rainfall and low temperature had a negative influence on the nectar secretion activity especially in genotypes having higher level of nectar secretion such as JLCMS 82A,JLCMS82B, JLCMSR1, and JLCMSR2.

The daily average, maximum, and minimum temperatures during July 18–22 were lower than those of days before rain. The average minimum temperature was only 14.1°C and the lowest temperature was 9.9°C on July 22 (Table 1).The minimum temperature in the early morning played an important role in the normal nectar secretion since the minimum temperature occurred just before or at the preactive and active stages of nectary development (Horner et al. 2003).

Nectar production was positively correlated with the lowest temperature on the day that samples were collected(Table 2). It was also significantly correlated with the average, lowest, and highest temperatures on the previous day. Nectar production was not correlated with air humidity on the sampling days.

3.3. Nectar production among genotypes

Nectar secretion of 27 genotypes was measured during flowering stage from 2008 to 2014 (except in 2011 and 2013). Large variation in nectar production was foundamong genotypes. Genotypes-tested were divided into three groups A-, B-, and R-lines. Within the same group,nectar production differed significantly among genotypes(Table 3). For A-lines, the highest nectar production was 0.137 μL in JLCMS101A and the lowest was 0.047 μL in JLCMS9A. The nectar production in the B-lines ranged from 0.053 μL (JLCMS9B) to 0.126 μL (JLCMS101B). The highest nectar production was 0.152 μL (JLCMR1) and the lowest nectar production was 0.81 μL (JLCMSR33)in R-lines. There were significant differences in nectar production among the three groups. Nectar production in R-lines was significantly higher than that of A- and B-lines.No difference was detected between A- and B-lines. Nectar production in the three lines within the same group also varied in different years. The highest nectar production was observed in 2012 and the lowest in 2008 for all groups.

Table 1 Meteorological factors during July 9–24, 2007

Date Temperature (°C) Humidity(%)Rainfall(mm)Average Max Min July 9 22.7 27.4 19.6 82.4 4.8 July 10 23.4 28.4 18.6 80.5 0 July 11 21.8 26.3 15.7 77.0 0 July 12 19.8 26.5 14.6 82.5 0 July 13 20.8 25.3 16.0 86.0 0.4 July 14 23.0 29.4 17.8 79.3 5.6 July 15 25.0 30.5 18.2 74.8 0 July 16 25.5 31.8 18.8 75.7 0 July 17 23.8 26.0 22.0 85.2 0 July 18 20.3 23.8 18.3 90.2 34.4 July 19 19.6 23.6 15.2 69.8 0 July 20 22.8 29.6 15.3 60.0 0 July 21 18.1 22.4 11.6 72.4 0 July 22 20.4 28.2 9.9 66.4 0 July 23 24.6 30.7 17.3 58.7 0 July 24 26.6 32.1 21.3 55.3 0

Fig. 3 Variation of nectar production of 12 genotypes from July 15 to 24 in 2007.

Table 2 Correlation coefficients among nectar production of three lines and meteorological factors1)

1) Min T, the minimum temperature; Pre Ave T, the average temperature of the previous day; Pre Max T, the maximum temperature of the previous day; Pre Min T, the minimum temperature of the previous day. ＊＊, significant at 0.01 probability level.

Type Min T Pre Ave T Pre Max T Pre Min T Humidity A-lines 0.522＊＊ 0.617＊＊ 0.469＊＊ 0.454＊＊ 0.184 B-lines 0.568＊＊ 0.694＊＊ 0.614＊＊ 0.430＊＊ 0.144 R-lines 0.656＊＊ 0.757＊＊ 0.620＊＊ 0.506＊＊ 0.104

3.4. Out-crossing rate among A-lines

significant differences of out-crossing rate were found among A-lines (Table 4). The highest out-crossing rate was 80.3% in JLCMS29 A and the lowest out-crossing rate was 7% in JLCMS89A. This difference provides an opportunity for breeders to select high out-crossing rate line or parents in breeding programs. The out-crossing rate of A-lines also varied in different years.

苏州牧星智能科技有限公司虽然从成立到现在只有短短两年多的时间，但却拥有一批经验丰富的研发人员和完善的技术储备，在进入市场后迅速成为了行业内一支不可忽视的力量。在2018上海CeMAT展会现场，记者采访了苏州牧星智能科技有限公司CTO黄志明先生。

3.5. Correlation between out-crossing rate and nectar production

The results of correlation analysis are shown in Table 5.The out-crossing rate of A-lines was significantly positively correlated (P＜0.01) with nectar production in A- and B-lines, and the correlation coefficients were 0.683 and 0.553, respectively. The nectar production in A-lines was also significantly positively correlated (P＜0.01) with the nectar production in B-lines, and the correlation coefficient was 0.729. Nectar is one of the most important foods and attractors for pollinators. Lines having high quantities of nectar might attract more pollinators leading to a higher out-crossing rate. Taking nectar production of a line as an indicator to select high out-crossing A- and B-lines in the early stage of breeding may greatly improve selection efficiency.

从论文的分析当中可知，深入探讨和分析无人机技术在地形图测绘中的应用进展具有重要的意义。本文通过阐释无人机航空摄影测量技术的应用原理，说明了地形图测绘中无人机航空摄影测量技术的应用进展：空中三角测量环节的分析运用、DOM工艺技术的科学应用、数字线划图的处理、单片正射影像的合理获得。望此次研究的结果，能得到相关工作人员的关注与重视，并从中获取一定的借鉴和帮助，以便推进我国地形图测绘中无人机技术的应用进程。

Table 3 Nectar production of three lines in soybean in different years

Different lowercase letters represent significant difference at the 0.05 level.

Type Genotype 2008 2009 2010 2012 2014 Year average A, B, R-lines average A-lines JLCMS101A 0.125 0.145 0.139 0.144 0.131 0.137 a 0.086 b JLCMS8A 0.131 0.113 0.119 0.109 0.133 0.121 b JLCMS29A 0.074 0.072 0.088 0.143 0.106 0.097 c JLCMS14A 0.085 0.084 0.088 0.116 0.097 0.094 c JLCMS82A 0.067 0.093 0.102 0.089 0.061 0.082 cd JLCMS47A 0.033 0.097 0.094 0.098 0.032 0.071 de JLCMS31A 0.047 0.056 0.056 0.094 0.050 0.061 ef JLCMS89A 0.048 0.044 0.084 0.056 0.083 0.063 ef JLCMS9A 0.037 0.038 0.053 0.074 0.031 0.047 f Average 0.072 c 0.082 bc 0.092 b 0.102 a 0.080 bc B-lines JLCMS101B 0.109 0.129 0.141 0.131 0.122 0.126 a 0.094 b JLCMS8B 0.099 0.131 0.150 0.135 0.106 0.124 a JLCMS82B 0.060 0.134 0.131 0.135 0.059 0.104 b JLCMS29B 0.065 0.094 0.109 0.113 0.132 0.103 bc JLCMS14B 0.062 0.097 0.100 0.134 0.069 0.092 bcd JLCMS31B 0.085 0.084 0.081 0.097 0.094 0.088 cd JLCMS47B 0.075 0.066 0.056 0.125 0.076 0.080 d JLCMS89B 0.052 0.078 0.106 0.064 0.081 0.076 d JLCMS9B 0.040 0.038 0.072 0.059 0.055 0.053 e Average 0.072 d 0.095 bc 0.105 ab 0.110 a 0.088 c R-lines JLCMSR1 0.156 0.100 0.178 0.191 0.134 0.152 a 0.116 a JLCMSR118 0.128 0.156 0.119 0.139 0.154 0.139 ab JLCMSR2 0.136 0.116 0.125 0.148 0.144 0.134 b JLCMSR26 0.091 0.109 0.100 0.141 0.151 0.118 ac JLCMSR75 0.131 0.113 0.066 0.107 0.173 0.118 c JLCMSR50 0.072 0.128 0.138 0.104 0.097 0.108 cd JLCMSR14 0.067 0.050 0.150 0.140 0.082 0.098 de JLCMSR4 0.066 0.128 0.113 0.118 0.064 0.098 de JLCMSR33 0.087 0.100 0.069 0.042 0.109 0.081 e Average 0.104 c 0.111 bc 0.118 ab 0.126 a 0.123 bc

Table 4 Out-crossing rate of cytoplasmic male sterile (CMS) A-lines in cages from 2008 to 2014 (%)

Different lowercase letters represent significant difference at the 0.05 level.

CMS A-lines 2008 2009 2010 2012 2014 Average JLCMS29A 77.7 86.7 76.3 82.3 78.3 80.3 a JLCMS101A 74.3 73.7 85.3 79.3 76.3 77.8 a JLCMS8A 70.3 78.7 71.5 76.3 70.3 73.4 b JLCMS82A 69.7 68.7 72.7 83.3 67.7 72.4 bc JLCMS14A 66.7 75.7 68.7 70.7 65.9 69.5 c JLCMS47A 25.7 40.7 31.7 30.3 26.7 31.0 d JLCMS9A 26.0 31.3 28.3 25.3 24.3 27.0 e JLCMS31A 8.3 7.6 6.3 7.2 10.3 7.9 f JLCMS89A 6.3 5.5 5.1 8.3 9.7 7.0 f Average 47.2 b 52.1 a 49.5 ab 51.4 a 47.7 b

4. Discussion

4.1. Favorable factors to nectar secretion and pollination

The relatively low seed-setting rate of female parents is one of the bottlenecks for commercialization of hybrid soybean.Several factors such as environmental conditions, species,and number of pollinators, and attractiveness of parents to pollinators may greatly influence the yield of hybrid seeds production (Sun et al. 2003; Zhao et al. 2010). Rainy and cold weather have been shown to be unfavorable for pollen transfer, and Erickson (1984a) indicated that temperatures above 22–24°C were required to ensure soybean nectar production.

The experiment was divided into two stages. First-stage experiments were performed in 2007 and aimed to explore basic rules of nectar secretion, including the rhythm of diurnal nectar secretion and the influence of weather on nectar secretion. Second-stage experiments were carried out from 2008 to 2014 to study the relationship between nectar secretion and the out-crossing rate of A-lines.

Table 5 Correlation coefficients among out-crossing rate of A-lines, nectar production of A-lines, and nectar production of B-lines in soybean

＊＊, significant at the 0.01 probability level.

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4.2. Reasons for R-lines had higher nectar production

All experiments were conducted in the experimental fields of the Soybean Research Institute located in Gongzhuling(43°30´N, 124°48´E), Jilin Province, China during 2007–2014, due to the continuous rainfall and low temperature in whole flowering time in 2011 and 2013, the data were collected. All plant materials were grown in caged plots. The space between rows was 60 cm and each plant was 8 cm apart within a row. This experiment was designed with three replicates. Each cage measured 6.0 m×18.0 m×2.5 m, and was constructed with 1.5 mm aperture nylon mesh. The plants were covered one week before flowering.All insects in covered cages were killed by spraying insecticides at least two weeks before sampling to eliminate potential negative effects on nectar secretion.

The diurnal nectar secretion of six genotypes is shown in Fig. 2. Flowers in most genotypes opened at 07:00 on clear days in July and sometimes opened at 06:30 in very good weather. Nectar could be detected at 06:00. For most genotypes except JLCMS82A and JLCMS82B, the quantity of nectar secretion increased and reached a peak point between 07:00–08:30 when the flowers were already opened; nectar secretion decreased gradually after that.Almost no nectar could be collected after 17:00. The nectar secretion of JLCMSR118 reached the highest level at 07:00,while JLCMSR2 had the highest level of nectar secretion at 08:30. Nectar production for JLCMS82A fluctuated: It reached the highest level at 08:30 and then decreased until 09:00. Nectar production of JLCMS82A increased and reached a higher level at 10:30. A small sub-peak was found at 13:00–13:30 for all genotypes.

4.3. Breeding methods for high out-crossing rate A-lines

Because of the significant positive correlation between nectar production of B-lines and out-crossing rate of A-lines, the measurement of nectar may be used to select A-lines with a high out-crossing rate by selecting B-lines with high nectar production. However the sampling operation of nectar is time-consuming work and it is difficult to handle a large number of breeding lines in a limited time. Further improvement of sampling method needs to be explored.

Volatile matter secreted from flowers was considered to be another factor for pollinator attraction (Erickson 1975,1983, 1984a; Horner 1998). Minimal data about the role of aroma in soybean pollen transfer are available so far,and detailed studies in this field are required to obtain these data. Higher and stable hybrid seed production is a complicated process and environmental, entomological,and genotypic factors should all be considered to produce low-cost hybrid seeds.

当摊铺好的混合料达到30m时，即可根据确定的碾压方案进行碾压。碾压分初压、复压、终压三个阶段，现场测温员负责设置碾压指示牌，指示牌交替向前，现场由专人负责记录碾压情况。

5. Conclusion

Soybean nectar secretion had diurnal variation. Secretion initiated at about 06:00 for most materials and reached a peak at 07:00–08:30 after flower opened, then the nectar secretion decreased gradually. A sub-peak appeared at about 13:00, while the nectar could not be detected at 17:00.

Nectar secretion was greatly influenced by the weather conditions. Rainy weather and low temperatures inhibited nectar secretion. The amount of nectar secretion increased gradually over time during periods of high temperature and no rainfall for several days.

There were obvious variations of nectar amount among different genotypes tested. There was no significant difference in nectar secretion between A- and B-lines. A-and B-lines with higher out-crossing rates secreted more nectar. The amount of nectar secretion of A- and B-lines were significant positively correlated with the out-crossing rate of A-lines.

Acknowledgements

This work was supported by the National Key Research and Development Program of China (2016YFD0101500,2016YFD0101502), and the Agricultural Science and Technology Innovation Project of Jilin Province, China(CXGC2017Z004).

三是少数上市公司为迎合庄家炒作本公司股票故意披露不真实信息，误导投资者的信息，不少投资者损失惨重。如2002年1月大庆联谊大股东对外宣布要对投资者实行高比例送股，引起该股价大涨和大跌，给投资者造成损失惨重。

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