Jatropha curcas L. (Euphorbiaceae) modulates stomatal traits in response to leaf-to-air vapor pressure deficit

Indonesia memiliki banyak tanah masam, tetapi penggunaan masih sangat sedikit karena kandungan nutrisi tanah masam rendah. Sementara itu, jarak pagar merupakan tanaman yang dapat tumbuh di berbagai jenis tanah (termasuk lahan marjinal) dan penggunaannya sebagai bahan baku biodiesel. Oleh karena itu, perlunya penelitian mengenai pertumbuhan jarak pagar pada tanah masam sebagai upaya untuk mengembangkan jarak pagar dan penggunaannya di Indonesia.Untuk memulai upaya, penelitian tentang berbagai genotipe jarak pagar di tanah masam telah dilakukan. Tujuan dari penelitian ini yaitu mempelajari genotipe jarak pagar yang berpotensi untuk tanah masam. Penelitian ini dilakukan di UPTD Pengembangan Teknologi Lahan Kering Singabraja, Kecamatan Tenjo, Bogor, Jawa Barat, dari November 2010-Agustus 201. Penelitian ini menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) dengan satu faktor yaitu genotipe. Hasil penelitian menunjukkan berbagai perbedaan pada pertumbuhan diantara genotipe-genotipe jarak pagar. Secara umum, ada lima genotipe jarak pagar yang terbaik di tanah masam (pH 5.0) yaitu Medan I-5-1, Dompu, IP-2P-3-4-1, Sulawesi, dan Bima M.

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Effect of Mycorrhizal Fungi on Gas Exchange of Micropropagated Guava Plantlets (Psidium guajava L.) during Acclimatization and Plant Establishment

HortScience ◽

10.21273/hortsci.33.3.501c ◽

1998 ◽

Vol 33 (3) ◽

pp. 501c-501

Author(s):

Andrés A. Estrada-Luna ◽

Jonathan N. Egilla ◽

Fred T. Davies

Keyword(s):

Tissue Culture ◽

Stomatal Conductance ◽

Gas Exchange ◽

Vapor Pressure ◽

Mycorrhizal Fungi ◽

Vapor Pressure Deficit ◽

Psidium Guajava ◽

Glomus Etunicatum ◽

Plant Establishment ◽

Use Efficiency

The effect of mycorrhizal fungi on gas exchange of micropropagated guava plantlets (Psidium guajava L.) during acclimatization and plant establishment was determined. Guava plantlets (Psidium guajava L. cv. `Media China') were asexually propagated through tissue culture and acclimatized in a glasshouse for eighteen weeks. Half of the plantlets were inoculated with ZAC-19, which is a mixed isolate containing Glomus etunicatum and an unknown Glomus spp. Plantlets were fertilized with modified Long Ashton nutrient solution containing 11 (g P/ml. Gas exchange measurements included photosynthetic rate (A), stomatal conductance (gs), internal CO2 concentration (Ci), transpiration rate (E), water use efficiency (WUE), and vapor pressure deficit (VPD). Measurements were taken at 2, 4, 8 and 18 weeks after inoculation using a LI-6200 portable photosynthesis system (LI-COR Inc. Lincoln, Neb., USA). Two weeks after inoculation, noninoculated plantlets had greater A compared to mycorrhizal plantlets. However, 4 and 8 weeks after inoculation, mycorrhizal plantlets had greater A, gs, Ci and WUE. At the end of the experiment gas exchange was comparable between noninoculated and mycorrhizal plantlets.

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