Vertical leaf spectral variation as an indicator of nitrogen nutrition status in rice plants

A field experiment was conducted to study the response of individual leaf spectral reflectance to five levels of nitrogen fertilizer treatments in rice (Oriza sativa L.) plants. Sampling was combined through a rice canopy at upper, medium and low levels for biomass, nitrogen and water content measurements with spectral signals from the leaves. The vertical gradients of leaf biomass, nitrogen and water contents were associated with the nitrogen availability during tillering, panicle formation, initial heading and heading. Rice plants treated with the lowest rate of N could be characterized with the lowest value of gradient in leaf biomass and leaf water content and the highest value of gradient in leaf N concentration. A spectral gradient of single reflectance (R), ratio (RVI) and normalized difference (ND) of two individual reflectances was defined as this yielded a better relationship between the spectral data and leaf nitrogen concentration. The results suggested the spectral gradients may be used as an improved diagnostic tool for nitrogen status. Project (49771056) supported by Natural Science Foundation of China(NSFC).     

Exploring youth engagement in agricultural development: the case of farmers’ children in the Philippines as rice crop manager infomediaries

Purpose: This paper explores the intersections between community development and youth development in an initiative that mobilized farmers’ children as Rice Crop Manager (RCM) infomediaries (information mediators). RCM is an ICT-enabled nutrient management application.

Design/Methodology/Approach: The study engaged 30 farmers’ children in high school level from the provinces of Pangasinan, Isabela, Camarines Sur, Iloilo, Bukidnon, and Davao del Norte from November 2016 to October 2017. They interacted with the research team (the authors) and the RCM-SMS platform that sends text messages regarding fertilizer recommendations. A staff member from the Agricultural Training Institute (ATI) also called the students for some follow-up questions. The research team conducted three rounds of interviews with the students concerning the messages and calls that they received and what they did with the information.

Findings: This study finds that farmers’ children can perform infomediary roles quite effectively. Academically excellent children and those involved in farm work performed best.

Practical Implications: The study provides guidance on similar initiatives tapping young people in agricultural development.

Theoretical Implications: This paper finds that while Community Youth Development (CYD) Theory provides a powerful lens in understanding community and youth development intersections, some identified outcomes may overlap and may not be very easy to observe. Hence, the identified outcomes may be revisited for clarity and to make them more all-encompassing.

Originality/Value: The paper documents actual parent-child interaction when the latter is mobilized to serve as an infomediary to access nutrient management-related information on rice.     

杂交稻分蘖和乳熟期~(32)P、~(14)C 分布与分蘖数和谷产量

8个杂交水稻组合的分蘖数,与分蘖期~(32)P及~(14)C在分蘖的分布(％)呈显著正相关,相关系数分别为r=0.569(n=21),r=0.532(n=22)。谷粒产量与分蘖期~(32)P在分蘖分布(％)的相关系数r=0.604(n=14)。谷粒产量与乳熟期~(14)C—葡萄糖同化物在稻穗分布(％)呈显著正相关,r=0.616(n=25)。高产杂交水稻威优64、汕优66、源优植和广优56的谷粒产量与~(14)C在乳熟期稻穗的分布和从剑叶的输出率相关系数大,低产杂交水稻汕A×芦36—1,D优66等相关系数小。讨论了~(32)P、~(14)C在分蘖和稻穗的分布动态,可作为预测杂交水稻产量的指标。     

彝族自然崇拜与稻作祭仪

彝族经济社会发展不平衡，各地自然崇拜的对象、形式、内容各有侧重和变异，与各自的生产生活方式相适应，但有一个共同的特点，即自然崇拜明显地打上了稻作文化的烙印，反映的主题是彝族人民从旱作到稻作文化的转型、融合和重组，并最后形成了以稻作生产为中心的稻作祭祀链。     

水稻珠心细胞的超微结构及酸性磷酸酶活性的动态变化

水稻在大孢子发生期间,珠心细胞保留了较多的分生组织细胞的特征:其细胞形态规则,细胞质浓厚,富含核糖体。核糖体游离于细胞质中,或附着于内质网及核外膜上。酸性磷酸酶的反应产物主要位于小液泡中,偶见于高尔基潴泡及小泡中。随着胚囊的分化,在珠心的内层出现一系列复杂的变化:①在细胞的液泡化过程中,频繁并持续地发生液泡对细胞质组分的吞噬,导致大液泡的形成,其中有很多的酸性磷酸酶反应产物。大液泡的进一步扩大和继后的破裂,引起细胞的解体;②粗面内质网槽库彭大并对细胞质进行分隔与吞噬,在核周腔内出现膜束縛内含物;③质膜与细胞壁分离,二者之间有大量的小泡及酸性磷酸酶反应产物。最后珠心细胞的原生质强烈收缩,转化为无结构的电子致密的残迹。     

将农杆菌Ti质粒携带的外源基因转入水稻细胞

未经特殊处理的农杆菌C58C1Rif~r菌株,与籼稻悬浮培养细胞共培养时,很少见有细菌的附着,也观察不到纤维丝的形成。但经复合酚类化合物预处理的菌株,与籼稻培养细胞在普通培养液,特别是在复合诱导培养液(培养过的番茄下胚轴切段、胡萝卜细胞及农杆菌的培养滤液)中共培养时,均可发现有较多的细菌附着于水稻细胞表面,并且菌体周围有纤维丝的形成。在复合处理组中,位于pGV3850:1103neo嵌合质粒T-DNA上的NPTⅡ基因及NOS基因在籼稻培养细胞中获得了转移与表达。     

不同品种水稻对乙草胺敏感性差异的生理原因探讨

用三种浓度的乙草胺处理对其敏感性不同的三种水稻（敏感品种华籼占、中抗品种粤优青占和抗性品种穗灵占）的发芽种子,水稻幼苗的呼吸速率不同程度受抑制,乙烯释放速率不同程度受干扰,两方面均以华籼占受影响最大,穗灵占受影响最小,粤优青占受影响居中;华籼占为"乙烯-呼吸谐变型";穗灵占为"乙烯-呼吸异变型";品种固有的"乙烯-呼吸型"的差异是不同品种水稻对乙草胺敏感性不同的内在生理原因。     

微生物肥料对杂交稻理化效应的研究

以三个杂交稻品种(华优89、银花丝苗、粤杂优268)为材料,用不同浓度的保得微生物肥叶面增效剂进行四种处理:A是以1:1000的浓度在插后回青期和分蘖后期各喷一次;B是以1:1000的浓度只在插后回青喷一次;C是以1:2000的浓度分别在插后回青期和分蘖后期喷一次。本实验测定的指标是叶绿素含量、呼吸强度、蛋白质含量、单株产量等。结果表明,施用保得微生物肥料的A、B、C三种处理以A处理效果最理想。     

沿江地区双季稻与水旱轮作的产量和效益分析

本文研究了沿江地区双季稻,露地花生—晚稻、地膜覆盖花生—晚稻等连作和轮作的产量和效益。结果表明：地膜覆盖花生—晚稻的效益极显著地高于其他处理,而且茬口衔接合理。     

浙西山区杂交水稻春季制种的气候条件及技术要点

阐述了浙西山区杂交水稻春制的有利气候条件和不利气候对春制的影响,提出了针对性技术措施,主要是中熟组合春制父本塑料大棚统一育秧,确定适宜的父母本播差及播期,及时预测和调节花期,加强肥水管理等。