Pollen grains of ramie materials with different ploidy level were observe with optical microscopy.The result indicated that pollen grain size was positively correlated with chromosome ploidy,relative coefficient index(r)was 0.970 8 in this study.Average pollen grain diameters were 16.30um for haploids,17.81 μm for diploids,22.00 μm for triploids and 24.76 μm for tetraploids. No vaieties effects appeared on this trait. Pollen grains of haploid varyed much in size and certain number of grotesque,wither and empty grains existed. From triploid materials,there were a few small grain pollens. These traits had value for identification of ramie chromosome ploidy materials.

对不同倍性苎麻的茎进行切片和组织离解显微观察结果表明,麻茎切面中麻皮所占百分率以单倍体最大,四倍体和二倍体次之,三倍体最小,分别为28.91%、27.05%、26.97%和24.77%;纤维层占截面面积百分率以二倍体最大,其次为单倍体,四倍体和三倍体最小,它们分别为16.80%、16.58%、15.52%和13.78%;纤维细胞直径和胞壁厚度随倍性的增加而增大;单纤维长度平均以二倍体最大,三倍体次之,单倍体最小,平均分别为8.49、7.96和6.93 cm.L/B(长/宽)比率以二倍体最大,其次为单倍体,三倍体最小,平均值分别为2 470.7、2 390.6和1 616.3,而单纤维宽度以单倍体最小,二倍体次之,三倍体最大,分别为29.30、33.87和49.20 μm;同一倍性材料变化较大,有待进一步研究.对大田不同倍性苎麻材料生物学特性观察,结果表明,随着染色体倍性的增加平均分株数/蔸有减少的趋势,而茎的平均粗度有增大的趋势,单倍体、二倍体、三倍体和四倍体每蔸分株数为5.83、5.30、3.77和3.65,平均茎粗分别为0.66、0.67、0.74和0.76 cm;平均高度以三倍体最高,其次为二倍体和四倍体,单倍体最矮;生长势以三倍体最强,二倍体和四倍体次之,单倍体最弱;抗寒性以四倍体最强,其次为二倍体,单倍体和三倍体最弱.单倍体和三倍体高度不孕.

Different ploidy ramie materials were studied via microscopic observation on stem sections and macerated fiber cells. Morphologic differences between different ploidy plants were analyzed. Average bark area percentages in ramie stem transection of haploids, tetraploids, diploids and triploids were 28.91, 27.05, 26.97 and 24.77% respectively. Average percentages of fiber layer area of diploids, haploids, tetraploids and triploids were 16.80, 16.58, 15.52 and 13.78% respectively. Average fiber cell diameter and cell wall thickness were increased along with the increase of the ploidy of the plants. Average fiber length of diploids, triploids and haploids were 8.49, 7.96 and 6.93 cm respectively. Average L/B (length/breadth) of diploids, triploids and haploids were 2470.7, 2390.6 and 1616.3 respectively. Average breadths of fiber of haploids, diploids and triploids were 29.30, 33.87 and 49.20 µm respectively. However, there were relatively large variations in the above characteristics among the ramie materials of the same ploidy levels. Field performance of different pboidy plants was also investigated. As the chromosome ploidy increasing, there was a tendency of declining in shoot number per plant and increasing in stem diameter. Average shoots per plant of haploids, diploids, triploids and tetraploids were 5.83, 5.30, 3.77 and 3.65 whereas their average stem diameters were 0.66, 0.67, 0.74 and 0.76 cm respectively. Triploids were the tallest, while haploids were the shortest. Triploids had strong growth vigour, diploids and tetraploids had moderate growth vigour, while haploids appeared to be lack of growth vigour. Cold stress tolerance of tetraploids were the strongest, diploid had the moderate tolerance, while haploids and triploids were the least tolerant to cold stress. Both haploids and triploids were sterile.

苎麻属于荨麻科是起源于我国的一种纤维与饲料作物,主要分布于热带、亚热带,少数达温带.我国的苎麻种质资源十分丰富,在苎麻品种资源的形态特征、农艺性状等方面已有较多的研究[1～3],建立了基于形态特征的分类系统.

采用盆栽干旱胁迫方法对苎麻品种圆叶青不同生育期抗旱性差异进行了研究,结果表明:在干旱胁迫下,苎麻品种圆叶青农艺性状、干物质积累和产量的胁迫指数均以苗期>工艺成熟期>旺长期,旺长期是苎麻品种圆叶青干旱胁迫敏感期.

分析了中国农业产业化现状和发达国家农业产业化的特点,并对中国台湾省的农业产业化道路进行了研究.指出与大陆地区农村情况相似的中国台湾省的农业产业化成功的关键在于推行了以农民利益为主体的农业产业化,建立了适应当地情况的农业产业化组织,台湾省的经验值得大陆地区借鉴.

经过氧化物酶和酯酶同工酶检测,发现湘苎3号变异株与供、受体间在酶谱上存在较大差异,说明异科DNA导入苎麻后出现的变异具有相应的生理生化机制.

化学药剂诱导的苎麻孤雌生殖后代植株的染色体数目变化很大 ,有单倍体、混倍体和非整倍体细胞 .在 2 8株孤雌生殖后代植株中 ,有 6株单倍体细胞超过 50 % .秋水仙素诱变株及多倍体杂交后代的染色体数目也呈现多样性 ,不同植株甚至同一植株的染色体数目均不一致 ,变化在 12～ 84之间 .对不同倍性苎麻植株分生组织的有丝分裂行为 ,观察到三极分裂、不均等分裂和落后染色体等异常有丝分裂现象 ,并对造成这种现象的原因作了初步的探讨 .

用抗旱指数(RI)等指标对苎麻基因型抗旱性进行了鉴定.结果表明:圆叶青、沅江黄壳早和沅江稀节巴为抗旱性较强的基因型,抗旱性较弱的基因型包括资兴绿麻和新宁箭杆麻.苎麻扦插(45天)苗在渗透胁迫4小时后的RwC(相对含水量)、POD(过氧化物酶)、Proline(脯氨酸)与抗旱指数呈正相关,而RPP(细胞膜透性)、MDA(丙二醛)则与抗旱指数呈负相关.采用模糊隶属法用上述5种生理生化指标对13个基因型抗旱性进行了早期鉴定,此法简便有效,准确性高.

The relationship between potassium absorption and root parameters in root morphology and physiology among various genotypes of ramie (Boehmeria nivea L ) were studied by soil pot culture and solution culture. The results showed that ramie genotypes with higher K absorption capacity had characters such as heavier root dry weight, especially the thin roots, larger total root area and active area for mineral absorption, larger root cation exchange capacity (CEC), larger V max and lower K m in K uptake kinetics.

在干旱胁迫下,抗旱性强的品种叶片相对含水量、细胞膜的稳定性高,随着干旱胁迫加强,抗旱性强的品种过氧化物酶活性提高,复水后下降快;而抗旱性弱的品种在一定限度胁迫下过氧化物酶活性增加,严重胁迫下则大幅度下降,然后复水后呈缓慢下降趋势 ;在干旱胁迫较轻时,抗旱性弱的品种积累游离脯氨酸多于抗旱性强的品种,而随着胁迫加强,抗旱性强品种游离脯氨酸积累强度大于抗旱性弱的品种;复水后抗旱性强的品种游离脯氨酸下降快,而抗旱性弱的品种则下降缓.干旱胁迫下苎麻叶片丙二醛(MDA)含量增加,随着胁迫加强,抗旱性弱的品种增加的速度快,抗旱性强的品种增加的速度慢.

在干旱胁迫下，抗旱性强的基因型叶片相对含水量、细胞膜的稳定性高和抗萎蔫能力强，苎麻叶片游离脯氨酸积累和过氧化物酶活性对干旱胁迫的反应存在基因型差异，随着干旱胁迫加强，抗旱性强的基因型过氧化物酶活性提高，复水后下降快；而抗旱性弱的基因型在一定限度胁迫下过氧化物酶活性增加，严重胁迫下则大幅度下降，然复水后呈缓慢下降趋势；在干旱胁迫较轻时，抗旱性弱的基因型积累游离脯氨酸多于抗旱性强的基因型，而随着胁迫加强，抗旱性强基因型游离脯氨酸积累强度大于抗旱性弱的基因型；复水后抗旱性强的基因型游离脯氨酸下降快，而抗旱性弱的基因型则下降缓。

本试验以苎麻品种芦竹青为材料,从有丝分裂和减数分裂两个方面进行研究,有丝分裂以墩稍扦插诱导萌发幼根,采用F—BSG法制备染色体标本,对其染色体核型和Giemsa带型进行的分析结果表明,苎麻的核型公式为2n=28=8(L)st+18(S)st+2(S)SAT,全为不对称的染色体,N·F.值与其染色体的条数相等,每组染色体的臂指数均大于78％,染色体长度比大于2.1:1,属于4B类核型。Giemsa C—带带型单一,短臂为全带,长臂为着丝点带。减数分裂以2％醋酸洋红压片,发现同一株上幼蕾着生的部位不同,其发育进度不一致,以着生在茎的中、上部的幼蕾发育快,同一枝梗上以着生于下部的幼蕾发育早,而同一幼蕾的PMC在减数分裂终变期、后期Ⅰ,末期Ⅰ以及后期Ⅱ、四分体等阶段同步程度高,同时观察到存在一定的高峰期。

用苎麻芦竹青嫩梢扦插诱导萌发幼根，采用F-BSG法制备染色体标本，对其染色体组型和Giemsa C-带带型进行研究。结果表明，苎麻的核型公式为2n=28=8(L)st+18(S)st+2(S)SAT，全为不对称的染色体，N、F值与其染色体条数相等，每组染色体臂指数均大于78％，染色体长度比大于2．1：1，属于4B类核型。Giemsa C-带带型单一，短臂为全带，长臂为着丝点带。