水稻品种分蘖特性对产量影响分析

分析了不同肥力水平条件下水稻品种分蘖特性对产量的影响．结果表明，１）穗数型品种分蘖力强，高肥栽培时单茎增多、叶面积增大、茎秆细弱、倒伏、结实率降低，不适于高产再高产的要求；２）高肥栽培时，分蘖力偏弱但有效分蘖期长，在较长分蘖期内逐渐产生分蘖的品种类型，可协调穗数、穗粒数和结实率的矛盾，从而获得高产；３）具有矮秆、中等分蘖能力、有效分蘖期长、有效分蘖率高、叶长而直立的穗重型品种，可协调高肥栽培时群体和个体的矛盾，有望实现超高产．     

龙须草分蘖规律初探

龙须草分蘖特性与禾本科多数植物类似,但是其分蘖能力极强,一颗种子苗一年可分百蘖以上。龙须草分蘖的多寡、快慢与品种、播种期、移栽期、温度、水分、光照、坡向和养分等因素有关,其中温度和水分是主导因子。龙须草耐旱性虽强,但以70％左右的田间持水量对分蘖最为有利。水热同步的夏季为龙须草分蘖高峰期。     

湘南油菜茬杂交早稻育秧方式初探

对湘南油菜茬杂交早稻的几种育秧方式进行了比较研究。提出适合于湘南油菜茬杂交早稻的育秧技术为温室（场地）两段培育带蘖或多蘖大秧技术。     

Stimulation of Regrowth in Barley by Application of Cytokinin

Abstract

The ability of cytokinin to stimulate regrowth in spring barley (Hordeum vulgare cv. Alexis) after cutting was investigated under glasshouse conditions. Application of 6-Benzyl-aminopurine (BA) to the irrigation water, from heading to termination of the trial, four weeks after grain ripening, significantly increased both tiller number and biomass after cutting at grain maturity. Cutting at earlier growth stages had no significant effect on these characteristics.     

ROLE OF BORON IN LEAF ELONGATION AND TILLERING DYNAMICS IN FINE-GRAIN AROMATIC RICE

This study was conducted to explore the role of boron (B) in seedling emergence, leaf elongation, and tillering dynamics. Boron was applied as seed priming. For priming seeds of two rice cultivars (Super Basmati and Shaheen Basmati) were soaked in B solutions having 0.001, 0.01, 0.1 and 0.5% concentrations. Substantial improvement in seedling emergence was observed from hydropriming and seed priming in 0.001 and 0.01% solutions; beyond this B concentration, emergence potential was suppressed. Seeds primed in 0.5% B solution even did not emerge. A linear increase in plant height was recorded up to 30 days from seeds primed in 0.001% solution. Similarly rate of leaf emergence and elongation and rate of tiller appearance were substantially improved in seedlings raised from seeds primed in 0.001% B solution. Overall B plays a significant role in leaf appearance, elongation and tillering dynamics of rice when used in very low concentration.     

割手密遗传作图最适分离群体的选择

[目的]筛选适合用于构建割手密遗传连锁图谱的分离群体,为后续的遗传连锁图谱构建和基因定位及遗传育种提供理论依据.[方法]基于“双假测交“理论,利用DNA水平上遗传差异较大且蔗糖分和分蘖率差异极显著的不同割手密无性系进行杂交获得3个不同杂交组合,对3个备选作图群体的分蘖率和蔗糖分进行变异、正态分布拟合分析及分子多态性分析.[结果]组合3（GXS85-12×GXS87-16）和组合13（云割①×田林）的分蘖率呈偏态分布,而组合5（GXS85-30×GXS87-16）的分蘖率呈近似正态分布;组合3和组合5的蔗糖分呈偏态分布,而组合13的蔗糖分呈近似正态分布.在分子多态性水平上,组合5亲本的遗传相似系数略高于组合3和组合13,而其后代平均遗传相似系数略低,但变幅较高.[结论]组合5（GXS85-30×GXS87-16,群体大小为245株）的分蘖率、蔗糖分遗传性相对稳定,群体来源比较广泛,分子多态性丰富,遗传多样性高,可作为分离群体用于构建遗传图谱.     

不同基本苗对湖南双季早稻产量形成的影响

为了更进一步地了解基本苗与早稻产量的关系,通过采用不同分蘖能力的水稻品种或组合（2个常规品种和2个杂交组合）,在大田条件下,研究不同栽插基本苗（2苗/穴,3苗/穴,4苗/穴）对湖南双季早稻产量及产量形成的影响,并对产量及其构成、干物质积累和茎蘖数进行考察。结果表明,随栽插基本苗的增加,早稻产量、有效穂数、总干物质重呈增加趋势,每穗粒数、结实率、收获指数则呈下降趋势,千粒重变化不大。出叶速度随栽插基本苗的增加而略有减慢。从茎蘖动态来看,在最高分蘖期（移栽后28天）以前,各个处理的分蘖速度基本相同,处理间的最高苗数表现出较大差异,但是基本苗较少的处理,后期的死亡分蘖数相对较少,至成熟期,各处理间的有效穂数差异较小。综合来看,在本试验条件下,早稻的每穴基本苗多,有利于产量形成,较易获得稳产高产。     

1,2,4-三氯苯胁迫对水稻分蘖盛期植株生长和生理特性的影响

在土培条件下,以对1,2,4-三氯苯(TCB)敏感性显著差异的宁粳1号(敏感)和扬辐粳8号(耐性)为对象,研究了不同浓度1,2,4-三氯苯(TCB)胁迫对两种水稻分蘖盛期生长和生理特性的影响。结果表明,不同浓度TCB胁迫下,敏感基因型宁粳1号最长根长、株高、单穴分蘖数、地上部和地下部干物重随胁迫程度加深均显著递减; 耐性基因型扬辐粳8号在低浓度(20 mg kg^-1) TCB胁迫下,最长根长、地上部和地下部干物重极显著增加,当中高浓度(40 mg kg^-1、60 mg kg^-1) TCB胁迫时,最长根长、株高、单穴分蘖数、地上部和地下部干物重显著下降。不同浓度TCB胁迫下,敏感基因型宁粳1号根系活力、叶绿素含量、叶片和根系可溶性蛋白质含量相对较低,叶片和根系超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性明显降低,O₂^?产生速率和丙二醛(MDA)含量显著增高; 耐性基因型扬辐粳8号在低浓度(20 mg kg^-1) TCB胁迫下,根系活力、叶片和根系的可溶性蛋白含量、SOD、POD、CAT活性极显著增加,O₂^?产生速率和MDA含量极显著降低,当中等浓度(40 mg kg^-1) TCB胁迫时,SOD、POD、CAT活性虽然增强,但O₂^?产生速率显著增加,MDA大量积累,当高浓度(60 mg kg^-1) TCB胁迫时,其根系活力、叶绿素含量极显著降低,根系中SOD、CAT活性显著降低,O₂^?产生速率和MDA含量显著增加。总之,低浓度TCB胁迫下,长势良好、叶片和根系可溶性蛋白质含量高、抗氧化系统清除活性氧能力强、膜脂过氧化程度低是耐性基因型扬辐粳8号区别于敏感型宁粳1号的主要特征。     

植物内源激素与水稻穗粒数的关系研究

对水稻分蘖期不同蘖位分蘖的五大类激素含量测定结果表明:各蘖位分蘖中赤霉素(GA3)、生长素(IAA)、脱落酸(ABA)和细胞分裂素(Z ZR)含量与每穗粒数呈正相关;生长初期增加分蘖中脱落酸含量,能促进生长素、赤霉素和细胞分裂素增加,提高分蘖的增产潜力,对蘖位优势发挥起重要作用。     

Identification and Cloning of Tillering-Related Genes OsMAX1 in Rice

Tillering is an important agronomic trait which has a direct impact on plant type and grain yield. Strigolactones are a class of important phytohormones regulating rice tillering. ATMAX1 is an important gene involved in strigolactone biosynthesis through encoding the protein P450 in Arabidopsis. Based on sequence BLASTp, we identified five homologous genes of ATMAX1 in rice, i.e., OsMAX1a, OsMAX1b, OsMAX1c, OsMAX1d and OsMAX1e. Among them, OsMAX1a and OsMAX1e showed stable and high expression in rice tissues. In addition, we observed that Os MAX1a and OsMAX1e can rescue the branched phenotype and the influences caused by MAX1 mutation in Arabidopsis. Moreover, the expression of OsMAX1a and OsMAX1e can respond to phosphate deficiency and different phytohormones, especially GR24, a strigolactone analogue. Therefore, it is concluded that Os MAX1a and OsMAX1e are involved in the biosynthesis of strigolactones and regulated rice tillering.