Induksi Umbi Mikro Kentang Secara In Vitro Pada Suhu Tinggi Dengan Beberapa Tuber Promoter

Abstract

Potato microtubers are the miniature of conventional seed tubers grown in the field. Producing potato microtuber in vitro at high temperature by applying many kinds of tuber promoting substances is similar to producing potato in the field at low elevation by applying the same tuber promoting substances. The objective of this research was to evaluate the performance of seven tuber promoters in inducing potato microtubers at high temperatures. Micro cuttings (6 weeks old) were grown at the liquid media of MS for stolon induction. Six weeks afterward, the media were moved to microtuber inducing media supplemented with tuber promoters ((FD, FD+10 COU, FD+20 COU, FD+30 COU, FD+40 COU, FD+50 COU, and IPB). The media were incubated in the dark at 20 + 2 o C and 29 + 2 o C. The results showed that, in general, high temperature inhibited crop growth and tuber formation. Individually, tuber promoter formula significantly affected microtuber emergence, in which IPB showed the slowest treatment in producing microtubers, the smallest number of tuber produced, and the smallest size of tubers. The interaction between temperature and tuber promoters were significantly affected the tuber formation, in which the fastest tuber formation (7,0 days ) was found in FD + 40 COU and the highest percentage of plant producing tubers was found in FD + 30 COU. Moreover, the highest number of microtuber and the heaviest weight of microtuber were found in FD (no Coumarin). It was safely concluded that all tuber promoters were best performed at low temperature. Should anyone wish to make those tuber promoters work better at high temperature, it is recommended to increase the concentration of Coumarin added to the formula of tuber promoting substances.Keywords: high temperature, in vitro, potato microtubers, tuber promoter INTISARI Umbi mikro kentang merupakan miniatur umbi kentang yang digunakan sebagai benih untuk penanaman di lahan. Produksi umbi mikro kentang pada suhu tinggi dengan zat pemacu pembentukan umbi (tuber promoter) dijadikan sebagai simulasi produksi kentang di dataran rendah dengan menggunakan formula tuber promoter. Tujuan penelitian ini adalah mengkaji pembentukan umbi mikro kentang pada suhu tinggi dengan berbagai formula tuber promoter. Stek mikro kentang berusia 6 minggu tanpa akar dan pucuk ditanam pada media cair untuk menginduksi pembentukan stolon. Pada usia 6 minggu stek mikro dipindahkan ke media induksi umbi mikro yang telah diberi

Inducing potato tuber formation at low elevation of tropical region by foliar spray of PGR mixtures at different application times

“…3). These findings suggested that the PGR Mixture, containing retardant and cytokinin could suppress the negative effect of GA at high temperature, as reported previously [4,13,19]. In fact, exogenous application of cytokinin was reported to promote tuber growth [20] while that of GA3 inhibited tuber initiation [21].…”

“…Furthermore, the highest tuber weight was found when PGR mixture was applied in 3,4,5,6 WAE. These suggested that PGR mixture needs only to be applied in 3,4,5 WAE to promote tuber formation, but it needed another week (3,4,5,6 WAE) to promote tuber growth to yield the highest tuber weight (Table 3). It suggested that an additional application of PGR mixture (daminozide and BAP) in week 6 was very effective, because week 6 is the time when potato tuber starts to accumulate starch [12].…”

“…The negative effects of GA at high temperatures might be overcome by application of growth retardants, such as Coumarin (COU), Paclobutrazol (PBZ), acting to inhibit GA biosynthesis in the plant. Adding Coumarin (25 ppm) or Paclobutrazol (500 ppm) to MS media supplemented with 10 ppm 2,4-D + 100 ppm Daminozide promoted tuber formation in vitro at 29 + 2 °C [4]. Previous works demonstrated that Paclobutrazol promoted tuber formation when potato crops grown at medium and low altitude [5,6].…”

“…The average daily temperature is about 29 + 2 °C during the day, which is quite warm for potato crops whose optimum temperature is 17 -20 °C [1]. Warm temperature has been reported to increase gibberellic acid (GA) biosynthesis in the bud of potato crops [2], promoting haulm growth [3], but preventing tuber formation [4].…”