Responses of the First Internodes of Hong Mang Mai Wheat to Ethylene,Gibberellins and Potassium

Abstract

Seedlings of Hong Mang Mai wheat ( Triticum aestivum L.) emerge from much deeper in the soil than do other cultivars by elongating their first internode. We examined the roles of ethylene, gibberellins (GA) and potassium in the elongation of the first internode in wheat cultivars. Although ethylene stimulated the elongation of the first internode of Hong Mang Mai in the dark, the ethylene evolution and the expression level of ethylene-receptor-like gene of this cultivar were not greater than those of other cultivars.

In Hong Mang Mai, gibberellin A₃ (GA₃) substantially stimulated the elongation of the first internode in the dark. Maximum elongation of the first internode was obtained by GA₃ at the concentrations of 2.89 × 10^–6 to 2.89 × 10^–7 M. This cultivar responded markedly to gibberellins A₁ and A₃ by elongating the first internode in the dark. A mixture of gibberellins A₄ and A₇ (GA₄₊₇) was not effective in inducing the elongation. Haruhikari, a cultivar having no GA -insensitive-reducing-height (Rht) genes, substantially responded to GA₃, but other cultivars did not. The differences in the sensitivity to GA could account, at least in part, for the varietal differences in the elongation of the first internode in wheat. Takune-komugi, a cultivar whose first internode elongates in response to ethylene, did not respond to GA₃. Thus, there are different mechanisms for the GA- and ethylene-stimulated elongation of the first internode in wheat.

Also, it was suggested that potassium uptake from the soil might function together with endogenous GA in inducing the elongation of the first internode in Hong Mang Mai wheat.     

Two novel QTLs regulate internode elongation in deepwater rice during the early vegetative stage

Deepwater rice possesses internode elongation ability to avoid drowning under deepwater conditions. Previous studies identified three QTLs regulating internode elongation ability on chromosomes 1, 3 and 12 using different populations. However, these QTLs only induce internode elongation in response to deepwater conditions from the 7-leaf stage and not during the early leaf stage. In this study, we detected two novel QTLs, qTIL2 and qTIL4 regulating deepwater response at the early leaf stage using an F₂ population derived from the cross between NIL1-3-12 carrying the three QTLs regulating deepwater response in T65 (O. sativa ssp. japonica) genetic background and C9285 (O. sativa ssp. indica, deepwater rice). Plants of the BC₂F₂ population derived from NIL1-3-12/C9285 and the RILs of T65/Bhadua (O. sativa ssp. indica, deepwater rice) possessing these QTLs as well as the three QTLs previously identified also showed internode elongation during the early leaf stage. These results indicate that qTIL2 and qTIL4 regulate early internode elongation and function in coordination with the three major QTLs under deepwater conditions. The results presented here would not only help define the mechanism of deepwater response in rice but also contribute in the breeding of deepwater tolerant rice that is adapted to various water depths.     

隐性高秆水稻02428h的eui基因在育种上的利用

为研究隐性高秆水稻“02428h”的长穗颈基因eui在减轻不育系包颈度中的利用价值,以02428h为父本,培矮64S为母本和轮回亲本,经过连续3次回交将02428h的eui基因导入培矮64S,转育成了具有长穗颈基因的“P8hS”。与培矮64S相比,P8hS的株高增加35.6 cm,主要是穗颈节和倒2节间长度增加所致。eui基因的导入不仅可使培矮64S的穗包颈得到彻底改善,而且对培矮64S及其杂种的主要经济性状具有促进作用。     

隐性长穗颈温敏核不育水稻穗颈节间的细胞学观察

以培矮64S为对照,对隐性长穗颈温敏核不育水稻长选3S穗颈节间的细胞进行比较分析,结果表明,隐性长穗颈不育水稻长选3S穗颈节间比对照培矮64S长14.6 cm,其纵列外层薄壁细胞和内层薄壁细胞数分别比培矮64S多1 248个和580个;外层薄细胞和内层薄壁细胞平均长度分别比培矮64S长23.3 µm和38.3 µm,尤其是中部区段     

杉木中幼龄林立地质量的生长截段评价

通过杉木生长截段与地位指数相关性的回归分析，证明生长截段法作为浙江省杉木人工中幼林的立地质量评价手段是切实可行的，生长截段法有助于解决浙江省大面积杉木中幼龄林的立地评价难题，研究结果表明，采用起测度高为胸高上方第２轮枝以上的５个完整节间长度作为杉木立地质量，精度最高，为实际应用，文中还编制了用这种生长截段间接或直接产地质量评价的数表，建立了数量化生长截段回归模型及得分表。     

水稻株高突变体的遗传分析

以伽马射线诱变籼稻品种"93-11"获得的5个长穗颈突变体"eR-1～eR-5"为材料,与野生型对比研究表明,5个长穗颈突变体植株、倒Ⅰ节间和倒Ⅱ节间分别显著增高和变长,穗长显著变长,突变体"eR-4"和"eR-5"分蘖能力显著提高,每穗粒数和结实率变化不显著,千粒重和单株产量均不同程度下降,其中突变体"eR-1"和"eR-2"的单株产量显著下降。等位性测定表明,突变体"eR-1"、"eR-2"、"eR-4"和"eR-5"的eui突变基因相互等位,并与已报道的eui基因等位,而与突变体"eR-3"的eui突变基因不等位。由此说明,"eR-3"是一个新的长穗颈突变体,其长穗颈性状受1对隐性核基因控制。     

水稻穗伸出度及若干茎秆叶片性状的遗传变异和相关

选用籼、粳、爪哇稻品种(系)100个,研究了穗伸出度等12个茎秆叶片性状的遗传变异和相关.结果表明:穗伸出度和最下部节间长的遗传变异系数最大:各茎秆叶片性状的广义遗传力均在95%以上;穗伸出度与叶片长、宽,第3、4节间长的遗传相关不显著.通径分析表明,对穗伸出度作用最大的是第1节间长度,其次为第2节间长,且与第3、4节间长和倒二叶长的遗传通径均为负效应.育种上,在选育利于异交的长穗颈、短冠层叶片性状的同时,可兼得降低基部节间长度,从而不因增长穗颈长度而降低抗倒性.     

棉秆轴向压缩特性的试验研究

采用电子万能试验机对棉秆进行轴向压缩试验研究。结果表明：干棉秆的弹性模量和轴向抗压强度明显高于湿棉秆；直径对棉秆的弹性模量和轴向抗压强度有影响，但无统一变化趋势；弹性模量和轴向抗压强度受节问影响。其平均值在节问2最大，节问5最小，节问3和节问4的值变化很小。     

丛生竹枝条扦插、埋节造林技术的研究

枝条扦插、埋节造林是丛生竹造林的新方法，在生产中越来越受重视。此项研究从立地条件、竹种和种源选择，母竹运输贮存，整地方式，造林密度，造林时间，应用生根剂等方面进行了较为系统的试验研究。结果表明：在立地条件较好的地方，选择枝条粗壮、秆壁较厚、易于生根的黄金间碧玉、甜龙竹、龙竹等大中型丛生竹种，扦插、埋节前先用相应的生长素处理，采用全面整地或带状清理大块状整地，于４月上旬至６月上旬造林，造林密度５ｍ×６ｍ，造林后进行封山育林和林农间作，能收到好的造林效果。与植苗造林相比较这两种造林方法具有繁植材料易得，利用率高，技术操作简单，造林成本低的优点。但造林效果不如植苗造林，仅适宜在立地条件较好的地区营造丛生竹林时采用。     

竹材节间细胞模型显示及论述

本文整理、总结近几年来竹材微结构方面的研究资料和数据，建立了竹材节间细胞的初步立体模型图，并尽可能地显示和论述细胞在纵切面的分布内容。立体图型增加了节间细胞整体认识上的直观性，对竹材应用的分析研究，对教学都是非常有益的。