256 



The Journal of Heredity 



f erred by means of (2) a small camel's 

 hair brush into (3) a small clean glass 

 vial. After a sufficient amount of 

 ]jollen is thus secured the vial is lightly 

 stoppered and labeled so that its 

 identity will not be lost when j^laced 

 among other but similar vials j^revious 

 to pollination. 



Should pollen-bearing flowers for an}' 

 reason not be plentiful a different 

 method of ])rocedure may be resorted to. 

 Tne flower buds are gathered, washed, 

 and allowed to open and cure in the 

 l^aper trays according to the usual 

 methods, but the ])ollen, instead of being 

 shaken from the dried anthers, is trans- 

 ferred together with them from the 

 paper tray direct to the small receiving 

 vial. Instead of using a camel's hair 

 brush for this transfer a clean forceps is 

 ]jreferred. because the waxy grape 

 jjollen is sufliciently adhesive to cause 

 the entanglement of large numbers of 

 the grains with the dried cluster material 

 and with the fine hairs of the brush, 

 thus incurring a great loss of pollen. 

 This waste may be prevented by the 

 use of a clean, fine pointed, steel forceps 

 to which only a comparatively small 

 amount of ])ollen adheres, and by not 

 shaking the i)ollen from the anthers 

 but keeping it confined until it is to be 

 applied to the jjistils of the female vine. 



FRESH POLLEN NEEDED 



Rotundifolia grape pollen ought to be 

 used i)referably on the same day or the 

 following day after it has been gathered, 

 but in case of necessity can be stored a 

 few days longer. In ordinary room 

 temperature it begins to deteriorate 

 rapidly after it is forty-eight hours old, 

 and not infrequently earlier, hence it is 

 best not to ]jrepare the pollen sooner 

 than twenty-four or thirty hours ])re- 

 vious to the time of jjollination. 



While the ])ollen is l)eing gathered 

 and cured the flowers of the female 

 ]jarent vine should be i:)re])ared for 

 eross-jjollination. This can be done 

 by either of two methods, all dei)end- 

 ing on the nature of such flowers: 

 (1) If these flowers bear the reflexed 

 type of stamen we know that they 



are self-sterile and also inter-sterile.' 

 Being thus affected with sterility they 

 need not have their stamens and 

 l^ollen removed previous to crossing 

 with other varieties. This knowledge 

 is of the highest importance l^ecause by 

 its ai^jjlication much time and labor can 

 be saved to the grape breeder. All 

 that is necessary then to prepare such 

 imperfect hemaphrodite grai)e flower 

 l>uds for the event of crossing is simply 

 to inclose them in bags before any of 

 them can open and thereby expose 

 their rece])tive pistils. (2) If the grape 

 flowers bear ujiright stamens we know 

 that they are self-fertile and the method 

 of preparing such flowers for cross-]Jol- 

 lination is the one that is usually adopted 

 by jjlant breeders of emasculating the 

 flower buds previous to bagging and 

 ])ollination. This can be done very 

 conveniently by operating on fully 

 matured buds in the afternoon, thirty- 

 six hours i^revious to the application of 

 jjollen to the prepared pistils. A slight 

 pressure firmly applied above the middle 

 of the bud with a pointed forceps will 

 usually cause the cap and also the in- 

 closed stamens to become detached 

 from the receptacle and leave the i)istil 

 bare. When all of the mature buds on 

 the cluster have been thus treated they 

 are thoroughly rinsed or dipped in clean 

 water to wash oft" and destroy all adher- 

 ing pollen, if there be any, that might 

 have been discharged by an anther 

 bursting during the emasculating opera- 

 tion. If this ])recaution is not strictly 

 observed many of the flowers will 

 become self-fertilized and per])lexing 

 results might be obtained. The jjre- 

 jjared flower clusters are now inclosed 

 within light paper or cloth bags to 

 await the process of artificial hand 

 pollination. 



The methods of transferring jjollen to 

 the pistils of the bagged flowers are 

 several and choice depends mainly on 

 the amount of available i:)ollen. When 

 this is ])lentiful the work can be materi- 

 ally hastened by the use of a small 

 camel's hair brush; when it is not so 

 abundant as one might wish, the thumb 

 nail method or the anther and forceps 



' North Carolina .Agricultural lilxpcTiincnt Station Bulletin No. 2W. 



