BREEDING WORK WITH BLACK- 

 BERRIES AND RASPBERRIES 



H. Ness 

 Horticulturist, Texas Agricultural Experiment Station 



OUR work with the genus Rubus, 

 which has for its object the 

 improvement of our cultivated 

 blackberries and dewberries, was trans- 

 mitted to me by my predecessor as 

 Horticulturist to the Texas Experiment 

 Station. The materials on hand in 

 1909, when I took charge, consisted of 

 about a dozen varieties of blackberries 

 and dewberries most commonly cul- 

 tivated in our region. To these I added 

 a few varieties of raspberries for the 

 sake of pollen. As fruit bearers, rasp- 

 berries are not dependable upon our 

 grounds. 



In looking the material over, I de- 

 cided to begin the work by crossing 

 those forms that showed the most 

 opposed differences in characters, hop- 

 ing thereby that the elements in the 

 composition of the progeny might be 

 more easily recognized and studied. 

 As a second part of the project, I 

 decided to grow as many seedlings 

 from each variety as possible with a 

 view to studying their variation and 

 the opportunity for selection. 



ORIGIN OF SPINELESS BLACKBERRIES 



From the McDonald Blackberry, a 

 native of Texas, introduced into culti- 

 vation by the Texas Nursery Company, 

 2,000 seedlings were brought into 

 bearing. This variety has a diffuse, 

 spiny growth, and is supposed to be a 

 natural hybrid. The 2,000 seedlings 

 fell readily into several more or less 

 distinct groups, one of which was 

 marked by its firm, almost coriaceous, 

 smooth, lustrous leaves of 3 to 5 

 ovate-lanceolate, nearly entire-mar- 

 gined leaflets. In this group, two 

 plants occurred with perfectly smooth 

 shoots, as free from spines as an 

 ordinary blade of grass. According to 

 the general habit of growth of these 

 two plants, I designated them, one as 



Spineless-diffuse, the other as Spine- 

 less-erect. From the Spineless-diffuse, 

 I have grown four generations of seed- 

 lings; and, though cross-pollination 

 with other forms was provided against 

 in the first generation only, the 

 majority of the progeny in each gen- 

 eration comes spineless and remarkably 

 true to the spineless type in all other 

 characters. My notes on the char- 

 acters of the fourth generation give the 

 following grouping of 200 young plants: 

 81 perfectly smooth, with all charac- 

 ters of the original type; 59 not 

 smooth, with spines more or less 

 evident, but otherwise typical; 60 

 plants not smooth, and of a different 

 type. 



The plants of the spineless group are 

 readily recognized when very small 

 by the form of the first leaf, which is 

 cordate or cordate-lanceolate with en- 

 tire or crenulate margins. The shape of 

 these leaves is so similar to certain 

 types of violets that they might, when 

 young, be passed off on the unsuspect- 

 ing as violets. 



In crossing the Spineless-erect with 

 the Early Harvest, two plants were 

 obtained. The spineless form in one 

 of these was so dominant that no 

 traces of the Early Harvest, the mother, 

 could be detected. This spineless F, 

 selfed gave 77 individuals, in which 

 the spineless grandfather was domi- 

 nant, and 130, in which the Early 

 Harvest, or the grandmother, was 

 dominant. None were absolutely 

 smooth, that is, without pubescence, 

 as in the true spineless type, but the 

 form of the first leaf of the 7 7 plants was 

 true to that type. 



EARLY HARVEST X AUSTIN MAYES 



My first attempts at hybridization 

 were, however, directed towards the 

 combination of two forms that I 



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