Mycorrhizal effects on the physiology of micropropagated chile pepper (Capsicum annuum L.) plantlets during acclimatization /
Chile ancho pepper (Capsicum annuum L. cv. San Luis) was used as a model plant system to study selected physiological adjustments and plant performance of tissue culture derived platelets during acclimatization and post-acclimatization. The elects of early mycorrhiza colonization were also character...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1999.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=731681091&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Chile ancho pepper (Capsicum annuum L. cv. San Luis) was used as a model plant system to study selected physiological adjustments and plant performance of tissue culture derived platelets during acclimatization and post-acclimatization. The elects of early mycorrhiza colonization were also characterized. During acclimatization micropropagated pepper plantlets experienced physiological changes that were critical to plantlet survival. During the first days after transplanting ex vitro to liner pots with soilless media, plantlet wilting was observed, which correlated with reduced leaf relative water content (RWC). This water stress was partially alleviated by reduction in stomatal conductance (g[]), confirming that the in vitro formed stomach were functional and able to regulate transpiration (E) to avoid desiccation.. Because of this stomatal control, platelets avoided excessive leaf dehydration recovered and survived. Prior to transplanting ex vitro, micropropagated pepper platelets showed typical heterotrophic/mixotrophic characteristics as indicated by a low photosynthetic rate (A). However, within 6 days after transplantation platelets had become acclimatized and autographic, which was confirmed by increased A, gs, and E. The stabilization and improvement in RWC of micropropagated platelets during the critical days of acclimatization and early post-acclimatization correlated with dramatic increases in plantlet growth. Acclimatization of mycorrhizal (AM) and non-colonized micropropagated chili pepper platelets was similar. Water deficits, stomatal control (reduction in gs and E), low A, low leaf chlorophyll content and poor initial plant growth occurred in both mycorrhizal and non-mycorrhizal planters during acclimatization. However, 3 and 5 days after transplanting and inoculation mycorrhiza enhanced gs and A. ABA concentration in leaf stem and roots increased during acclimatization when the relative humidity (RH) was gradually reduced from high to lower levels; however, mycorrhizal plantlets accumulated less ABA levels deleing peak water deficits than did the non-mycorrhizal plantlets. AM fungi began to colonize host pepper platelets within 3 days after inoculation, attaining 45% root colonization 48 days after inoculation. Mycorrhiza improved plant growth, leaf chlorophyll content, A and mineral nutrition - particularly N, P, K. Benefits provided by mycorrhiza can occur within few days after inoculation, which suggest the importance of early ex vitro inoculation with rapid colonizing mycorrhiza. |
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| Item Description: | Vita. "Major Subject: Horticulture". |
| Physical Description: | xiv, 132 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 97-111). |