Raspberry Plant Cv. `Isabel`

This invention relates to a new and distinct cultivar of raspberry plant that has been given the variety name or denomination `Isabel`. The new cultivar was developed from hybridization of the selection B36.7 (an unpatented variety) as the seed parent with the selection C44.1 (an unpatented variety) as the pollen parent. The parents were crossed by Stephen Wilhelm in 1987, whereafter fruit and seed were collected to produce seedlings for field planting in Watsonville, Calif., in 1988. The new variety was selected from these seedlings by Carlos Fear in 1989 for their large, attractive fruit. Since its selection the `Isabel` plants have been evaluated in several noncommercial experimental plantings in Watsonville, Calif. The `Isabel` variety has been asexually propagated by in vitro shoot tip culture, root sucker division and root cuttings, and has been shown to maintain the desired and distinguishing characteristics after propagation over several generations.

The `Isabel` raspberry plant produces a relatively early primocane crop which begins in July and continues until late October. The floricane crop begins in early May and continues until about mid-July. Both the primocane and floricane yields are high relative to other comparable varieties. The fruit of the `Isabel` raspberry plant is large and remains consistently so throughout its harvest period. The fruit has a very pleasant flavor and darkens only slightly after harvest.

FIG. 1 is a photograph of an `Isabel` floricane mature leaf and fruiting shoot, showing various stages of fruit development.

FIG. 2 is a photograph of an `Isabel` primocane shoot.

FIG. 3 is an interpretative drawing showing the cultivar banding patterns for the enzymes, MDH (malate dehydrogenase), PGI (phosphoglucoisomerase) and PGM (phosphoglucomutase).

Throughout this specification, color names beginning with a small letter signify that the name of the color, as used in common speech, is aptly descriptive. Color names beginning with a capital letter designate color values based on The R.H.S. Colour Chart published by The Royal Horticultural Society of London, England.

The following description is a detailed description of the `Isabel` raspberry cultivar and the fruit produced thereby, as grown in Watsonville, Calif. between 1991 and 1994, and is believed to apply to plants of the `Isabel` variety grown in similar conditions of soil and climate elsewhere.

The `Isabel` fruit size is large and does not decline as much as most varieties throughout the fruiting cycle. Fruit color darkens only slightly after harvest. The fruit of the `Isabel` plant is average or moderate in its ease of separation and of moderate firmness at harvest. Post harvest fruit rot resistance is intermediate in comparison with many selections and varieties.

The `Isabel` variety has moderate susceptibility to late leaf rust and powdery mildew. Resistance to root rots is unknown and cold tolerance of the new variety has not been established.

The new variety is particularly characterized and distinguished from other cultivars by it high yields on both primocanes and floricanes. It is further distinguished by its large, bright red fruit of excellent flavor, which maintains its large size through the harvest season. The `Isabel` variety also fruits earlier in the spring than most other cultivars.

`Isabel` is distinguished from its pollen parent, selection C44.1, by fruiting earlier in the spring, having larger fruit size, and yielding more fruit. The new variety is distinguished from its seed parent by having a higher yielding capacity with more uniform fruit shape.

Tables 1 and 2 below present morphological information about the new `Isabel` raspberry cultivar.

In addition to the foregoing morphological description, and to provide further means for identifying the new variety and distinguishing it from some other somewhat similar and/or related raspberry varieties, the new `Isabel` variety has been analyzed to obtain an indication of its genetic makeup. Specifically, leaves of the `Isabel`, `Hollins` (U.S. Plant Pat. No. 8,027), `Summit` (unpatented), `Wilhelm` (U.S. patent applied for), `Sweetbriar` (U.S. Plant Pat. No. 4,486), and `Joe Mello` (U.S. Plant Pat. No. 6,493) varieties were electrophoretically analyzed, the patterns designated and procedures utilized being per those described by J. C. Cousineau and D. J. Donnelly, "Use of Isoenzyme Analysis to Characterize Raspberry Cultivars and Detect Cultivar Mislabeling," HortScience, vol 27 (9):1023-1025 (1992). The results of the electrophoresis analysis are presented in Table 3 below, the letters representing the cultivar banding patterns for each enzyme as shown in FIG. 3, taken from the above article.