GA3 and GA4(gibberellins)play an important role in controlling gravitropism and tension wood formation in woody angiosperms.In order to improve our understanding of the role of GA3 and GA4 on xylem cell formation and ...GA3 and GA4(gibberellins)play an important role in controlling gravitropism and tension wood formation in woody angiosperms.In order to improve our understanding of the role of GA3 and GA4 on xylem cell formation and the G-layer,we studied the effect of GA3 and GA4 and uniconazole-P,which is an inhibitor of GA biosynthesis,on tension wood formation by gravity in Fraxinus mandshurica Rupr.var.japonica Maxim.seedlings.Forty seedlings were divided into two groups;one group was placed upright and the other tilted.Each group was further divided into four sub-groups subjected to the following treatments:3.43 x 10-9 lunol acetone as control,5.78 x 10-8 lunol gibberellic acid(GA3),6.21 x 10-8 lunol GA4,and 6.86 x 10-8 lunol uniconazole-P.During the experimental period,GAs-treated seedlings exhibited negative gravitropism,whereas application of uniconazole-P inhibited negative gravitropic stem bending.GA3 and GA4 promoted wood fibers that possessed a gelatinous layer on the upper side,whereas uniconazole-P inhibited wood formation but did not inhibit the differentiation of the gelatinous layer in wood fibers on the upper side.These results suggest that:(i)both the formation of gelatinous fibers and the quantity of xylem production are important for the negative gravitropism in horizontally-positioned seedlings;(ii)GA3 and GA4 affect wood production more than differentiation of the gelatinous layer in wood fibers;G-layer development may be regulated by other hormones via the indirect-role of GA3 and GA4 in horizontally-positioned F.mandshurica seedlings rather than the direct effect of GAs;and(iii)the mechanism for upward wood stem bending is different to the newly developed shoot bending in reaction to gravity in this species.展开更多
针对水稻插秧机插秧后,田间的苗情信息缺乏及时有效的检测,秧苗可能会出现漂秧、少叶等情况,提出了一种水稻秧苗检测与分类识别方法。首先,利用无人机采集秧苗图像,并将图像分为合格、漂秧和少叶秧苗3种类别。然后,在YOLOv8n基础上引入S...针对水稻插秧机插秧后,田间的苗情信息缺乏及时有效的检测,秧苗可能会出现漂秧、少叶等情况,提出了一种水稻秧苗检测与分类识别方法。首先,利用无人机采集秧苗图像,并将图像分为合格、漂秧和少叶秧苗3种类别。然后,在YOLOv8n基础上引入SE(Squeeze-and-Excitation)注意力机制,使模型在特征提取过程中更加精准地捕捉到与水稻秧苗相关的特征;融入VOV-GSCSP模块,能够有效地整合模型不同层次的特征信息,增强对水稻秧苗的检测能力;融入CARAFE(Content-Aware ReAssembly of FEatures)上采样算子,有效地减少了模型的参数量,降低了模型的计算复杂度和存储需求,以此增强模型的特征重建能力。最后,进行验证试验,结果表明,该网络模型对于秧苗形态识别的平均准确率达90.26%,比基础模型YOLOv8n提高了1.54个百分点,mAP@0.5提高了1.52个百分点,mAP@0.5-0.95提高了3.35个百分点,检测速度达到70.42 f/s,能够满足对秧苗分类的识别精度,可对后期补秧计划提供数据支持。展开更多
基金Supported by a Scholarship from the Japanese Ministry of Education(07456073)Scientific Research Foundation for the Returned Overseas Chinese Scholars.
文摘GA3 and GA4(gibberellins)play an important role in controlling gravitropism and tension wood formation in woody angiosperms.In order to improve our understanding of the role of GA3 and GA4 on xylem cell formation and the G-layer,we studied the effect of GA3 and GA4 and uniconazole-P,which is an inhibitor of GA biosynthesis,on tension wood formation by gravity in Fraxinus mandshurica Rupr.var.japonica Maxim.seedlings.Forty seedlings were divided into two groups;one group was placed upright and the other tilted.Each group was further divided into four sub-groups subjected to the following treatments:3.43 x 10-9 lunol acetone as control,5.78 x 10-8 lunol gibberellic acid(GA3),6.21 x 10-8 lunol GA4,and 6.86 x 10-8 lunol uniconazole-P.During the experimental period,GAs-treated seedlings exhibited negative gravitropism,whereas application of uniconazole-P inhibited negative gravitropic stem bending.GA3 and GA4 promoted wood fibers that possessed a gelatinous layer on the upper side,whereas uniconazole-P inhibited wood formation but did not inhibit the differentiation of the gelatinous layer in wood fibers on the upper side.These results suggest that:(i)both the formation of gelatinous fibers and the quantity of xylem production are important for the negative gravitropism in horizontally-positioned seedlings;(ii)GA3 and GA4 affect wood production more than differentiation of the gelatinous layer in wood fibers;G-layer development may be regulated by other hormones via the indirect-role of GA3 and GA4 in horizontally-positioned F.mandshurica seedlings rather than the direct effect of GAs;and(iii)the mechanism for upward wood stem bending is different to the newly developed shoot bending in reaction to gravity in this species.
文摘针对水稻插秧机插秧后,田间的苗情信息缺乏及时有效的检测,秧苗可能会出现漂秧、少叶等情况,提出了一种水稻秧苗检测与分类识别方法。首先,利用无人机采集秧苗图像,并将图像分为合格、漂秧和少叶秧苗3种类别。然后,在YOLOv8n基础上引入SE(Squeeze-and-Excitation)注意力机制,使模型在特征提取过程中更加精准地捕捉到与水稻秧苗相关的特征;融入VOV-GSCSP模块,能够有效地整合模型不同层次的特征信息,增强对水稻秧苗的检测能力;融入CARAFE(Content-Aware ReAssembly of FEatures)上采样算子,有效地减少了模型的参数量,降低了模型的计算复杂度和存储需求,以此增强模型的特征重建能力。最后,进行验证试验,结果表明,该网络模型对于秧苗形态识别的平均准确率达90.26%,比基础模型YOLOv8n提高了1.54个百分点,mAP@0.5提高了1.52个百分点,mAP@0.5-0.95提高了3.35个百分点,检测速度达到70.42 f/s,能够满足对秧苗分类的识别精度,可对后期补秧计划提供数据支持。
