TWO TYPES OF ALBUGO-INDUCED GALLS ON IPOMOEA PENTAPHYLLA AND THEIR MORPHOGENETIC INTERPRETATION

1966 ◽  
Vol 44 (5) ◽  
pp. 535-540
Author(s):  
Hardev Singh ◽  
Krishna Bedi

Ipomoea pentaphylla Jacq. is a twining, hirsute annual. After infection by Albugo ipomoeae-panduranae (Schw.) Swingle, two types of galls develop on the stem—bud and cerebriform. The bud gall originates from an infected bud while the cerebriform gall arises from the internode. The two types are distinct from each other in their morphology, anatomy, rate of development, and morphogenesis. The bud gall is of the organoid type while the cerebriform gall is of the histioid type. Tissues of the bud gall grown under in vitro conditions give rise to a structure like the cerebriform gall. The very distinct morphology of the two types has been interpreted on the basis of the possible organizing influence of the shoot apical meristem.

2018 ◽  
Vol 86 (1) ◽  
Author(s):  
Imron Riyadi ◽  
Darda EFENDI ◽  
Bambang S PURWOKO ◽  
Djoko SANTOSO

AbstractA right combination of cytokinin is able to support the process of callus differentiation to somatic embryo formation in plant somatic embryogenesis. Liquid culture application could increase the efficiency of in vitro culture process on plants. This research aimed to determine the best concentration of TDZ combined with kinetin for callus differentiation to  somatic embryo of sago palm on three culture methods. Plant material used was embryogenic callus derived from tips meristem culture from sucker of Alitir sago palm. Callus was cultured on modified MS media added with: 0.0, 0.1, 0.5 and 1.0 mg/L TDZ combined with 0.5 mg/L kinetin for 12 weeks with subcultures every 6 weeks. Three culture methods used were suspension, temporary immersion system (TIS), and solid media. There were 12 treatments with 4 replicates. The results showed that the highest number of somatic embryos was achieved on TIS culture with 1.0 mg/L TDZ and 0.5 mg/L kinetin in 6 weeks (167.3 embryos/flask) and 12 weeks (389.2 embryos/flask) with its fresh weight of 18.4 g and 29.1 g, respectively. The highset survival rate in final culture (12 weeks) was achieved on TIS culture with 1.0 mg/L TDZ and 0.5 mg/L kinetin (100%). The shortest time for somatic embryos expression was achieved on TIS culture with 1.0 mg/L TDZ and 0.5 mg/L kinetin in two weeks after culture. Histological analysis of early-stage somatic embryos showed the presence of dense and compact cellular arrangements which formed growth spot axis for shoot or SAM (shoot apical meristem) and root or RAM (root apical meristem) that connected each other. [Key words: culture method, embryogenic callus, Metroxylon sagu Rottb., kinetin, sago palm, TDZ]   AbstrakAplikasi kombinasi sitokinin yang tepat dapat mendorong proses diferensiasi kalus membentuk embrio somatik pada proses embriogenesis somatik tanaman. Penggunaan metode kultur cair dapat meningkatkan efisiensi proses kultur in vitro tanaman. Penelitian ini bertujuan untuk menentukan konsentrasi TDZ terbaik dikombinasikan dengan kinetin dalam proses diferensiasi kalus membentuk embrio somatik tanaman sagu pada tiga metode kultur. Bahan tanam penelitian  berupa kalus embriogenik tanaman sagu asal kultur meristem pucuk dari anakan sagu jenis Alitir. Kalus dikulturkan pada media modifikasi dengan penambahan  TDZ dengan konsentrasi 0,1; 0,5; dan 1,0 mg/L dikombinasikan dengan kinetin 0,5 mg/L selama 12 minggu yang disubkultur pada umur 6 minggu. Metode kultur yang digunakan terdiri atas tiga macam yaitu: kultur suspensi, sistem perendaman sesaat (SPS) dan media padat. Perlakuan terdiri atas 12 kombinasi perlakuan dengan empat ulangan. Hasil penelitian menunjukkan bahwa rerata jumlah embrio somatik tertinggi dicapai pada perlakuan metode kultur SPS dengan TDZ 1,0 mg/L baik pada umur kultur 6 minggu (167,3 buah) maupun umur 12 minggu (389,2 buah). Rerata bobot segar tertinggi juga diperoleh pada perlakuan metode kultur SPS dengan TDZ 1,0 mg/L  pada umur kultur 6 minggu (18,4 g) dan  12 minggu (29,1 g). Rerata daya hidup kultur akhir (12 minggu) tertinggi  sebesar 100% diperoleh pada perlakuan SPS. Induksi embrio somatik  tercepat yakni setelah  dua minggu diperoleh pada  metode kultur SPS dengan TDZ 1,0 mg/L dikombinasikan dengan kinetin 0,5 mg/L. Analisis histologi embrio somatik stadium awal  menunjukkan adanya susunan sel yang rapat dan kompak yang menyusun semacam poros atau berkas titik tumbuh tunas atau SAM (shoot apical meristem) maupun akar atau RAM (root apical mersitem) yang saling terhubung.[Kata kunci: kalus embriogenik, metode kultur, kinetin, TDZ, sagu, Metroxylon sagu]


1970 ◽  
Vol 18 ◽  
pp. 104-107 ◽  
Author(s):  
ME Haque ◽  
D Rezwana ◽  
MA Islam ◽  
B Sikdar

Context: Pumpkin (Cucurbita maxima) is very important vegetable crop. It is damaged by several types of diseases, especially viral diseases which reduce the total yield of pumpkin. This is very difficult problem and such type of problem can be overcome by meristem culture. Objectives: To develop suitable protocols for indirect regeneration of pumpkin plant through shoot apical meristem.   Materials and Methods: Meristems were isolated from 15-21 days in vivo grown plants by collecting shoot tips and were prepared (0.2-0.5 mm) under 4X zoom stereo-microscope remaining two leaves primordia. Inoculation of explants was made singly per culture vessel in semisolid MS fortified with different concentrations and combinations of cytokinin and auxin.   Results: Among different concentrations, 1.0 mg/l BAP showed best response for callus induction. Calli were sub cultured for shoot formation in MS containing BAP singly or combination with GA3 and 1.5 mg/l BAP + 0.1 mg/l GA3 gave better result. In vitro regenerated shoots were rooted well in ½ strength MS with 0.5 mg/l IBA and micro plants were acclimatized successfully in natural condition.   Conclusion: Indirect regeneration of pumpkin plants through shoot apical meristem has been established.   Keywords: Growth regulators; in vitro regeneration; Pumpkin; Cucurbita maxima. DOI: http://dx.doi.org/10.3329/jbs.v18i0.8784 JBS 2010; 18(0): 104-107


2008 ◽  
Vol 133 (5) ◽  
pp. 653-662 ◽  
Author(s):  
James S. Busse ◽  
Senay Ozgen ◽  
Jiwan P. Palta

Shoot tip necrosis has been attributed to calcium deficiency in in vitro cultures, resulting in death of the stem tip, the loss of apical dominance, and axillary branch development. Using an in vitro shoot culture system with Solanum tuberosum L. cv. Dark Red Norland, we studied the development of injury symptoms at the microscopic and tissue levels at a range of media calcium concentrations varying from 6.8 to 3000 μm. Light and electron microscopic studies revealed that the primary injury due to calcium deficiency was the death and collapse of expanding pith cells below the shoot apex. The structure and organization of the shoot apical meristem was the same when plants were cultured on sufficient or suboptimal media calcium concentrations. However, the apical meristem senesced following subapical shoot tissue collapse. Death of the shoot apical meristem was a secondary effect of calcium deficiency, resulting in loss of apical dominance. Studies with 45Ca indicated that calcium was distributed in a gradient along the shoot, with highest concentration at the base and the lowest at the apex. Shoot tip necrosis developed after 20 days of culture on the suboptimal calcium concentration medium. The development of these symptoms and axillary shoot growth was associated with the lack of calcium accumulation in the shoots. Our results provide evidence that a primary injury of calcium deficiency is localized in the expanding pith cells below the shoot apical meristem and this injury results in the collapse of subapical cells. Death of the shoot apical meristem is a secondary injury resulting from calcium deficiency.


2021 ◽  
Vol 947 (1) ◽  
pp. 012039
Author(s):  
Linh Tran Minh Hong ◽  
Tu Cam Trinh ◽  
Viet Trang Bui ◽  
Huong Thanh Tran

Abstract Rose is the most popular ornamental flower all over the world, which is used as garden plants and cut flowers. In the case of Rosa hybrida L. ’Red Rose’, flowering provides the major developmental transition from the vegetative to the reproductive stage, and reproduction is one of the most important phases in an organism’s life cycle. In this study, the morphological and physiological changes during the flower development of rose, which is planted in the garden, and roles of plant growth regulators on the flowering of in vitro vegetative shoots of rose were analyzed. The development of a flower includes three stages: the shoot apical meristem, floral meristem, floral bud. Levels of cytokinin, auxins, and gibberellins increased in the transition of meristem from the shoot apical meristem to the floral meristem stage. Plant growth regulators have important effects on the shoot apical meristem cell division and flowering. The combination of 0.5 mg.L−1 GA3, 0.1 mg.L−1 NAA, 2.5 or 3.0 mg.L−1 BA to Murashige and Skoog (MS) medium induces the floral transition of the in vitro vegetative shoots with the highest percentage (41%) as well as growth and development in comparison to the other treatments after 10 weeks. Then, the in vitro floral meristem continuously developed into a flower bud after 12 weeks.


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