Elymus canadensis×Secale cereale Amphiploids. II. Chromosome Constitutions and Pairing of Open-Pollinated Progeny

Eleven C₂ and two C₃ 0pen-pollinated plains from Elymus canadensis × Secale cereale amphiploid plants (2n = 6x = 42, SSHHRR) were examined for chromosome constitution and meiosis. Chromosome numbers of the progeny varied: 2n = 26, 27, 28, 36, 37, 39, 40, and 41. Elimination of portions of genome constituents were made at random and were irregular in all o the progeny. Monosomic (2n = 41) and nullisomic (2n = 40) plants lost one to two E. canadensis or S. cereale chromosomes and showed average of 17 to 18 bivalents and 4 to 5 univalents per cell at Ml. The C₂, aneuploid plants with 36 to 41 chromosomes seemed to result from selfing or intercrossing among; the C₁ amphiploid plants, while the plants of 2n = 26 to 2S (6–9 II + 10–141) might originate from outcrosses of the C_l amphiploid to S. cereale. Bivalent pairing might be preferentially intragenomic (S-S, H-H, or R-R). The occurrence of multivalents indicates a low potential of both intragenomic and intragenomic pairing; Pollen of the lour plants showed poor stainability (1 to 13 %) and no seed set in any of the progeny.     

Morphology and Cytology of Tissue Culture Derived Octoploid of Elymus canadensis and its Selfed Progeny

Thirty five octoploids (2n = 56). two aneuploids (2n = 54), and one hexaploid (2n = 42) were obtained from the self-fertilized octoploid which was regenerated from the immature inflorescence culture of Elymus canadensis. The octoploid regenerant showed gigas leaves and stems but reduced tillering and fertility. The selfed octoploid progeny varied from genotype to genotype for all of the characters investigated. Hexaploid was morphologically superior to other ploidy levels. Its dry matter yield was 34 % to 40 % higher than the octoploids and the tetraploids but fertility markedly decreased to 7.4 %. Chromosome pairing at metaphase 1 in the octoploid regenerant and its selfed progeny — octoploid, aneupioid. and hexaploid — were 2.57IV +0.83III + 21.23II + 0.971; 3.06IV + 1.06III + 19.66II + 1.251; 2.23IV + 0.85III + 16.54II + 4.69I; and 0.41IV + 8.34III + 8.25II ? 3.141 per microsporocyte, respectively. High frequency of trivalents in hexaploid indicated that it is a doubled triploid. Unequal chromosome disjunction, laggards, and chromatid bridges were commonly observed at the anaphase stage in the first and second meiotic division.     

甘蓝型油菜和芥菜型油菜杂种小孢子培养获得再生植株

利用分离小孢子培养首次从甘蓝型油菜和芥菜型油莱种间杂种(甘芥杂种)中获得了胚和再生植株。所用的培养程序是,将甘芥杂种小孢子在蔗糖浓度为13％的液体NLN培养基中32℃下暗培养2天,转入25℃暗培养3周,再在光照条件下振荡培养一周后转入再生培养基(B_5)。供试的8个正反交甘芥杂种,有4个对培养有反应,其中3个均为以甘蓝型油菜为母本的杂种。杂种911186(甘蓝型)×851336(芥菜型)的胚产量明显高于其他杂种,未发现杂种花粉育性与小孢子胚产量存在显著相关。多数再生植株形态上介乎两个亲本之间,已开花的植株多为不育类型。讨论了亲本基因型对杂种小孢子胚胎发生的影响和小孢子衍生植株的可能用途。     

Production of Primary Triticale from Calluses of Immature Abnormal Hybrid Embryos between Triticum durum and Secale cereale

Plant regeneration was attempted in callus induced from the immature abnormal hybrid embryos between T. durum and S. cereale, using 4-Huorophenoxyacetic acid as a growth regulator. In particular, the relationship of numerical variation in chromosomes between the callus tissues and the regenerated plants was investigated. Cytological observation revealed that there was no distinctive numerical difference between the shoot-forming (SF) and the non-shoot-forming calluses and also between the SF calluses and the regenerated plants. The root-tips of regenerated plants consisted of cells having various chromosome numbers, including the expected 2 n = 3 ×= 21 (genomes, ABR) of which the frequency was 69.8 %. The regenerated plants showed partial fertility, notwithstanding that the hybrid plants were expected to be sterile. Since the frequency of abnormal embryos was about 90 % in this cross, the utilization of abnormal embryos was demonstrated by use of callus culture.     

Shoot Regeneration from Anther Culture of Sunflower (Helianthus annuus) and Some Interspecific Hybrids as Affected by Genotype and Culture Procedure

Anther culture has been demonstrated to be an applicable technique for the development of doubled haploid, i. e. homozygous lines of many crop species. In some species, androgenetic doubled haploids have already been shown to be a useful tool for breeding. However, anther culture results in sunflower have been rather unsatisfactory up to now. As in other species, anther culture response of sunflower (Helianthus sp.) is strongly affected by physical, nutritional, physiological and genetical factors. By testing a number of different culture parameters, i. e. donor plant stages, culture media and conditions, and appropriate schedule could be worked out for the successful regeneration of shoots – at least for a number of sunflower lines and interspecific hybrids.     

加拿大紫荆‘森林火焰’组培快繁技术研究

以紫叶加拿大紫荆（Cercis canadensis ‘Forest Pansy’）当年生嫩枝为试验材料,探讨不同培养基和植物生长调节剂如6-BA、IBA、NAA、TDZ对试管苗增殖以及生根的影响。结果表明：最适增殖培养基为DKW+TDZ 0.03 mg/L+PVP 0.5 mg/L;生根培养基为1/2 MS + IBA 25 mg/L+AC 0.6 mg/L。此体系中增殖系数可达4.27,生根率73.3%。     

Plant Regeneration from the Hybridization of Brassica juncea and B. napus Through Embryo Culture

Crosses were made to produce interspecific hybrids between Brassica napus × B. juncea and their reciprocals with the aid of embryo culture techniques. A better response of hybrid embryo culture was obtained from two cross combinations of B. juncea × B. napus (Ames 24521 × Huyou 15 and Vittasso × Zheshuang 72) than from their reciprocals. Embryo culture was more effective in terms of plant regeneration when embryos were cultured in vitro at 15 days after pollination (DAP), while more calli were initiated when embryos were excised and cultured at 10 DAP. A better response was observed on the MS medium with 0.3 mg l^?1 naphthylacetic acid (NAA) + 1.5 mg l^?1 6‐benzylaminopurine (BAP) and with 0.3 mg l^?1 NAA + 2.0 mg l^?1 BAP. Callus formation and plant regeneration on these two media reached 55.43 and 26.65 %, and 66.98 and 24.61 %, respectively.     

陆地棉抗病品种中521植株再生的研究

以农艺性状优良且抗枯黄萎病的陆地棉品种中521的下胚轴为外植体,采用固液结合的体细胞培养方法建立细胞悬浮系并进行植株再生的研究。结果表明,愈伤组织的诱导以MS 1.0 mg.L-1IBA 0.05 mg.L-1KT 0.1 mg.L-12,4-D 30g.L-1葡萄糖的固体培养基为最佳;体细胞胚的形成以MS 0.01 mg.L-1IBA 0.01 mg.L-1KT 0.005 mg.L-12,4-D 1.0g.L-1谷氨酰胺的液体培养基为最佳,悬浮30 d后可以发现体细胞胚的形成。之后转接入四种不同的MSB固体培养基上诱导再生植株形成,发现MSB 2 g.L-1谷氨酰胺 0.5 g.L-1天冬酰胺 30g.L-1蔗糖 6.0 g.L-1琼脂为最佳培养基,且发现此方法比全程固体培养缩短了体细胞再生的周期,此品种在本研究建立的再生体系下植株再生周期为6个月左右。     

Chromosomal instability in cell- and tissue cultures of tomato haploids and diploids

Summary The effect of the tissue culture system, the genotype and the ploidy level of the plant material used as explant source on the stability of the ploidy level of plants regenerated fromcell and tissue cultures of tomato was investigated. In addition the use of the chloroplast number in guard cells as a measure for ploidy level was evaluated. Haploids of tomato were very instable, which instability was observed already in somatic root tip and leaf cells. The number of regenerated plants that retained the original ploidy level differed significantly between the tested haploids. The plants that were regenerated from leaf explants of diploids were predominantly diploid in contrast to the plants regenerated from established callus cultures and protoplast where the majority was tetraploid.     

Chromosomal Stability in the Backcross Progenies of Pentaploid Hybrids between Avena sativa L. and A. maroccana Gdgr.

In a backcrossing programme to transfer desirable characters from wild Avena maroccana Gdgr. to cultivated oats, A. sativa L., meiotically stable plants in BC₁F₃ and BC₂F₂ progenies were isolated. The recovery of stable genotypes with 2n = 6×= 42 chromosomes indicated that two backcrosses are enough for such a programme. The cytological observations in various backcross generations are presented and discussed.     

黑糯米成熟胚愈伤组织培养及植株再生研究

对贵州惠水黑糯、黑糯141成熟胚愈伤组织培养及再生条件的研究结果表明,分步消毒可以减少外植体的污染率,在附加2,4-D 2 mg/L的NBD 1培养基中,成熟胚愈伤组织诱导率较高,分别为93.84%、90.52%。愈伤组织的继代培养是分化前必不可少的过程,适当干燥处理及合适的激素配比能够提高愈伤组织分化率,贵州惠水黑糯分化率为95.18%,黑糯141分化率为89.38%。2个黑糯米品种在附加NAA 0.5 mg/L的生根培养基中均能正常生根。     

洋葱幼蕾离体培养与植株再生的研究

通过对洋葱幼蕾的离体培养试验,探讨了影响洋葱幼营愈伤组织诱导和植株再生的影响因素,即激素浓度和配比、基因型、低温预处理,花蕾大小和移栽条件,基本掌握了影响洋葱幼蕾愈伤组织诱导和植株再生的关键技术,建立起一套高频率的再生体系,为进一步利用洋葱组织培养技术奠定了基础。     

不同凝固剂对陆地棉体细胞胚胎发生和植株再生的影响

以陆地棉种质系珂字312和陆地棉标准系TM-1为材料,结合优化的陆地棉体细胞培养体系,系统地研究了琼脂、Gelrite和Phytagel3种培养基凝固剂对愈伤组织的诱导、胚性愈伤的增殖、体细胞胚状体的发生和植株再生的影响。结果表明,用Phytagel作为培养基的凝固剂,可显著改善陆地棉体细胞培养过程中的褐化问题,并具有提高胚性愈伤组织增殖速度、体细胞胚胎发生和植株再生频率等作用。Gelrite虽也能改善棉花体细胞培养中的褐化问题,但因水化现象严重而影响胚性愈伤组织增殖和体细胞胚状体发生,其效果不如Phy-tagel。因此,在陆地棉体细胞培养过程中的胚性愈伤组织诱导、体细胞胚状体发生和植株再生过程中,宜用Phytagel作为培养基的凝固剂,而无菌苗培养和愈伤组织诱导仍可以选用琼脂凝固剂。     

秋水仙碱及热击与低温诱导对油菜小孢子胚状体成苗率的影响

甘蓝型冬油菜F1杂种分离小孢子直接用500 mg/L秋水仙碱处理15 h,在NLN-13培养液中培养,并于32℃和30℃分别热击暗培养3 d和7 d后转入24℃下培养,胚胎发生好,5周后产生大量正常胚体.将这些发育优异的胚体移入固体MS培养基后即进行10 d低温诱导(2℃),常温(24℃)光下培养能很好地萌发并直接、快速地再生植株,其萌发胚率和成苗率     

In tergeneric crosses with Fragaria and Potentilla. II. Crosses between the progeny of Fragaria moschata x Potentilla fruticosa and the original parents

Summary An aneuploid hybrid (2n=23) of Fragaria moschata (2n=42) and Potentilla fruticosa (2n=14) was backcrossed with pollen of both parents, separately and combined in a pollen mixture. Seven vigorous progeny were obtained. The origin of the exeptional chromosome numbers, 2n=44, 49, 63, 63, 65, 67, 67, is discussed, and it is shown that each of the numbers could be produced by the fertilisation of unreduced and double unreduced gametes of the hybrid by normally reduced gametes of one of the parental species.     

用“对话”试验探索植物组织培养机制并建立适用性广的小麦组织培养方法

以小麦为试材，以揭示培养因素与培养结果之间的对应关系为目标，通过用类似“对话”试验的方法探索了基因型、外植体类型、培养基、培养条件等在植物组织培养中的作用和影响。结果表明，基因型不影响愈伤组织的形成，只影响和决定愈伤组织的质量。外植体既影响愈伤组织的形成，又影响愈伤组织的质量。由外植体类型造成的愈伤组织质量差异并不亚于由基因型所造成的差异，但其作用主要表现在离体培养的早期阶段。培养基除了向培养物提供营养外，不同培养基之间的差别更主要地表现为对愈伤组织质量的不同调控效应。一般情况下，2,4-D和NH₄⁺对细胞分裂、愈伤组织生长表现为促进作用；细胞分裂素、NO₃^-对细胞分裂、愈伤组织生长表现为抑制作用。光照具有类似细胞分裂素的效应。温度变化对愈伤组织质量也具有调控作用。各培养因素的作用实际上均转化为生理生化效应。借助这种认识，所有培养因素的作用均可在生理生化水平得到解释。据此，植物组织培养的可预见性和可控性得到大幅度增强。通过本研究，为小麦组织培养建立了有较广泛适用意义的方法。     

Resistance to Polymyxa betae in Beta Species of the Section Procumbentes, in Hybrids with B. vulgaris and in Monosomic Chromosome Additions of B. procumbens in B. vulgaris

Plant regeneration from callus cultures of Allium trifoliatum subsp. hirsutum fertile accession F-370, was studied as a means for clonal multiplication and germplasm storage of Allium spp. Callus was induced on in votro-cultured basal leaf explants. Best proliferation was obtained on modified BDS medium supplemented with (mg/1): 0.75 picloram, 2.0 benzyl adenine, and 900 casein hydrolysate. Shoot and root organogenesis were obtained in 3 to 5 month old subcultured calli, on BDS or MS medium supplemented with (mg/1): either 0.03 picloram or no auxin, 2 BA or 2-isopentenyladenine, and 900 casein hydrolysate. Direct bulb formation, without shoot elongation, occurred on BDS medium with 10 mg/1 IBA. Under these conditions, callus formation and organogenesis were not obtained with A. trifoliatum subsp. hirsutum var. sterile, a male-sterile genotype. Most regenerants were phenotypically normal, but some abnormal shoots were also observed, i.e. shoots with vitrified or extremely broad leaves. Isozyme polymorphism analysis of seven proteins in the latter regenerants, and in several callus cultures, revealed significant deviation from the original pattern in esterase, 6-phosphogluconate dehydrogenase and superoxide dismutase. No such deviations were detected in normal regenerated plants.